MDEV-25325 built-in documentation for performance_schema tables

Improve documentation of performance_schema tables by appending COLUMN
comments to tables. Additionally improve test coverage and update corresponding
tests.

mysql-test/suite/perfschema/r/dml_accounts.result

@@ -23,3 +23,14 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.accounts WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'accounts'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='accounts';
+column_name	column_comment
+USER	The connection's client user name for the connection, or NULL if an internal thread.
+HOST	The connection client's host name, or NULL if an internal thread.
+CURRENT_CONNECTIONS	Current connections for the account.
+TOTAL_CONNECTIONS	Total connections for the account.

mysql-test/suite/perfschema/r/dml_cond_instances.result

@@ -18,3 +18,12 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.cond_instances WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'cond_instances'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='cond_instances';
+column_name	column_comment
+NAME	Client user name for the connection, or NULL if an internal thread.
+OBJECT_INSTANCE_BEGIN	Address in memory of the instrumented condition.

mysql-test/suite/perfschema/r/dml_esgs_by_account_by_event_name.result

@@ -24,3 +24,18 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_stages_summary_by_account_by_event_name WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'events_stages_summary_by_account_by_event_name'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_stages_summary_by_account_by_event_name';
+column_name	column_comment
+USER	User. Used together with HOST and EVENT_NAME for grouping events.
+HOST	Host. Used together with USER and EVENT_NAME for grouping events.
+EVENT_NAME	Event name. Used together with USER and HOST for grouping events.
+COUNT_STAR	Number of summarized events, which includes all timed and untimed events.
+SUM_TIMER_WAIT	Total wait time of the timed summarized events.
+MIN_TIMER_WAIT	Minimum wait time of the timed summarized events.
+AVG_TIMER_WAIT	Average wait time of the timed summarized events.
+MAX_TIMER_WAIT	Maximum wait time of the timed summarized events.

mysql-test/suite/perfschema/r/dml_esgs_by_host_by_event_name.result

@@ -24,3 +24,17 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_stages_summary_by_host_by_event_name WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'events_stages_summary_by_host_by_event_name'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_stages_summary_by_host_by_event_name';
+column_name	column_comment
+HOST	Host. Used together with EVENT_NAME for grouping events.
+EVENT_NAME	Event name. Used together with HOST for grouping events.
+COUNT_STAR	Number of summarized events, which includes all timed and untimed events.
+SUM_TIMER_WAIT	Total wait time of the timed summarized events.
+MIN_TIMER_WAIT	Minimum wait time of the timed summarized events.
+AVG_TIMER_WAIT	Average wait time of the timed summarized events.
+MAX_TIMER_WAIT	Maximum wait time of the timed summarized events.

mysql-test/suite/perfschema/r/dml_esgs_by_thread_by_event_name.result

@@ -24,3 +24,17 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_stages_summary_by_thread_by_event_name WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'events_stages_summary_by_thread_by_event_name'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_stages_summary_by_thread_by_event_name';
+column_name	column_comment
+THREAD_ID	Thread associated with the event. Together with EVENT_NAME uniquely identifies the row.
+EVENT_NAME	Event name. Used together with THREAD_ID for grouping events.
+COUNT_STAR	Number of summarized events, which includes all timed and untimed events.
+SUM_TIMER_WAIT	Total wait time of the timed summarized events.
+MIN_TIMER_WAIT	Minimum wait time of the timed summarized events.
+AVG_TIMER_WAIT	Average wait time of the timed summarized events.
+MAX_TIMER_WAIT	Maximum wait time of the timed summarized events.

mysql-test/suite/perfschema/r/dml_esgs_by_user_by_event_name.result

@@ -24,3 +24,17 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_stages_summary_by_user_by_event_name WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'events_stages_summary_by_user_by_event_name'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_stages_summary_by_user_by_event_name';
+column_name	column_comment
+USER	User. Used together with EVENT_NAME for grouping events.
+EVENT_NAME	Event name. Used together with USER for grouping events.
+COUNT_STAR	Number of summarized events, which includes all timed and untimed events.
+SUM_TIMER_WAIT	Total wait time of the timed summarized events.
+MIN_TIMER_WAIT	Minimum wait time of the timed summarized events.
+AVG_TIMER_WAIT	Average wait time of the timed summarized events.
+MAX_TIMER_WAIT	Maximum wait time of the timed summarized events.

mysql-test/suite/perfschema/r/dml_esgs_global_by_event_name.result

@@ -23,3 +23,16 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_stages_summary_global_by_event_name WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'events_stages_summary_global_by_event_name'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_stages_summary_global_by_event_name';
+column_name	column_comment
+EVENT_NAME	Event name.
+COUNT_STAR	Number of summarized events, which includes all timed and untimed events.
+SUM_TIMER_WAIT	Total wait time of the timed summarized events.
+MIN_TIMER_WAIT	Minimum wait time of the timed summarized events.
+AVG_TIMER_WAIT	Average wait time of the timed summarized events.
+MAX_TIMER_WAIT	Maximum wait time of the timed summarized events.

mysql-test/suite/perfschema/r/dml_esms_by_account_by_event_name.result

@@ -24,3 +24,37 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_statements_summary_by_account_by_event_name WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'events_statements_summary_by_account_by_event_name'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_statements_summary_by_account_by_event_name';
+column_name	column_comment
+USER	User. Used together with HOST and EVENT_NAME for grouping events.
+HOST	Host. Used together with USER and EVENT_NAME for grouping events.
+EVENT_NAME	Event name. Used together with USER and HOST for grouping events.
+COUNT_STAR	Number of summarized events
+SUM_TIMER_WAIT	Total wait time of the summarized events that are timed.
+MIN_TIMER_WAIT	Minimum wait time of the summarized events that are timed.
+AVG_TIMER_WAIT	Average wait time of the summarized events that are timed.
+MAX_TIMER_WAIT	Maximum wait time of the summarized events that are timed.
+SUM_LOCK_TIME	Sum of the LOCK_TIME column in the events_statements_current table.
+SUM_ERRORS	Sum of the ERRORS column in the events_statements_current table.
+SUM_WARNINGS	Sum of the WARNINGS column in the events_statements_current table.
+SUM_ROWS_AFFECTED	Sum of the ROWS_AFFECTED column in the events_statements_current table.
+SUM_ROWS_SENT	Sum of the ROWS_SENT column in the events_statements_current table.
+SUM_ROWS_EXAMINED	Sum of the ROWS_EXAMINED column in the events_statements_current table.
+SUM_CREATED_TMP_DISK_TABLES	Sum of the CREATED_TMP_DISK_TABLES column in the events_statements_current table.
+SUM_CREATED_TMP_TABLES	Sum of the CREATED_TMP_TABLES column in the events_statements_current table.
+SUM_SELECT_FULL_JOIN	Sum of the SELECT_FULL_JOIN column in the events_statements_current table.
+SUM_SELECT_FULL_RANGE_JOIN	Sum of the SELECT_FULL_RANGE_JOIN column in the events_statements_current table.
+SUM_SELECT_RANGE	Sum of the SELECT_RANGE column in the events_statements_current table.
+SUM_SELECT_RANGE_CHECK	Sum of the SELECT_RANGE_CHECK column in the events_statements_current table.
+SUM_SELECT_SCAN	Sum of the SELECT_SCAN column in the events_statements_current table.
+SUM_SORT_MERGE_PASSES	Sum of the SORT_MERGE_PASSES column in the events_statements_current table.
+SUM_SORT_RANGE	Sum of the SORT_RANGE column in the events_statements_current table.
+SUM_SORT_ROWS	Sum of the SORT_ROWS column in the events_statements_current table.
+SUM_SORT_SCAN	Sum of the SORT_SCAN column in the events_statements_current table.
+SUM_NO_INDEX_USED	Sum of the NO_INDEX_USED column in the events_statements_current table.
+SUM_NO_GOOD_INDEX_USED	Sum of the NO_GOOD_INDEX_USED column in the events_statements_current table.

mysql-test/suite/perfschema/r/dml_esms_by_digest.result

@@ -25,3 +25,39 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_statements_summary_by_digest WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'events_statements_summary_by_digest'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_statements_summary_by_digest';
+column_name	column_comment
+SCHEMA_NAME	Database name. Records are summarised together with DIGEST.
+DIGEST	Performance Schema digest. Records are summarised together with SCHEMA NAME.
+DIGEST_TEXT	The unhashed form of the digest.
+COUNT_STAR	Number of summarized events
+SUM_TIMER_WAIT	Total wait time of the summarized events that are timed.
+MIN_TIMER_WAIT	Minimum wait time of the summarized events that are timed.
+AVG_TIMER_WAIT	Average wait time of the summarized events that are timed.
+MAX_TIMER_WAIT	Maximum wait time of the summarized events that are timed.
+SUM_LOCK_TIME	Sum of the LOCK_TIME column in the events_statements_current table.
+SUM_ERRORS	Sum of the ERRORS column in the events_statements_current table.
+SUM_WARNINGS	Sum of the WARNINGS column in the events_statements_current table.
+SUM_ROWS_AFFECTED	Sum of the ROWS_AFFECTED column in the events_statements_current table.
+SUM_ROWS_SENT	Sum of the ROWS_SENT column in the events_statements_current table.
+SUM_ROWS_EXAMINED	Sum of the ROWS_EXAMINED column in the events_statements_current table.
+SUM_CREATED_TMP_DISK_TABLES	Sum of the CREATED_TMP_DISK_TABLES column in the events_statements_current table.
+SUM_CREATED_TMP_TABLES	Sum of the CREATED_TMP_TABLES column in the events_statements_current table.
+SUM_SELECT_FULL_JOIN	Sum of the SELECT_FULL_JOIN column in the events_statements_current table.
+SUM_SELECT_FULL_RANGE_JOIN	Sum of the SELECT_FULL_RANGE_JOIN column in the events_statements_current table.
+SUM_SELECT_RANGE	Sum of the SELECT_RANGE column in the events_statements_current table.
+SUM_SELECT_RANGE_CHECK	Sum of the SELECT_RANGE_CHECK column in the events_statements_current table.
+SUM_SELECT_SCAN	Sum of the SELECT_SCAN column in the events_statements_current table.
+SUM_SORT_MERGE_PASSES	Sum of the SORT_MERGE_PASSES column in the events_statements_current table.
+SUM_SORT_RANGE	Sum of the SORT_RANGE column in the events_statements_current table.
+SUM_SORT_ROWS	Sum of the SORT_ROWS column in the events_statements_current table.
+SUM_SORT_SCAN	Sum of the SORT_SCAN column in the events_statements_current table.
+SUM_NO_INDEX_USED	Sum of the NO_INDEX_USED column in the events_statements_current table.
+SUM_NO_GOOD_INDEX_USED	Sum of the NO_GOOD_INDEX_USED column in the events_statements_current table.
+FIRST_SEEN	Time at which the digest was first seen.
+LAST_SEEN	Time at which the digest was most recently seen.

mysql-test/suite/perfschema/r/dml_esms_by_host_by_event_name.result

@@ -24,3 +24,36 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_statements_summary_by_host_by_event_name WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'events_statements_summary_by_host_by_event_name'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_statements_summary_by_host_by_event_name';
+column_name	column_comment
+HOST	Host. Used together with EVENT_NAME for grouping events.
+EVENT_NAME	Event name. Used together with HOST for grouping events.
+COUNT_STAR	Number of summarized events
+SUM_TIMER_WAIT	Total wait time of the summarized events that are timed.
+MIN_TIMER_WAIT	Minimum wait time of the summarized events that are timed.
+AVG_TIMER_WAIT	Average wait time of the summarized events that are timed.
+MAX_TIMER_WAIT	Maximum wait time of the summarized events that are timed.
+SUM_LOCK_TIME	Sum of the LOCK_TIME column in the events_statements_currentd table.
+SUM_ERRORS	Sum of the ERRORS column in the events_statements_current table.
+SUM_WARNINGS	Sum of the WARNINGS column in the events_statements_current table.
+SUM_ROWS_AFFECTED	Sum of the ROWS_AFFECTED column in the events_statements_current table.
+SUM_ROWS_SENT	Sum of the ROWS_SENT column in the events_statements_current table.
+SUM_ROWS_EXAMINED	Sum of the ROWS_EXAMINED column in the events_statements_current table.
+SUM_CREATED_TMP_DISK_TABLES	Sum of the CREATED_TMP_DISK_TABLES column in the events_statements_current table.
+SUM_CREATED_TMP_TABLES	Sum of the CREATED_TMP_TABLES column in the events_statements_current table.
+SUM_SELECT_FULL_JOIN	Sum of the SELECT_FULL_JOIN column in the events_statements_current table.
+SUM_SELECT_FULL_RANGE_JOIN	Sum of the SELECT_FULL_RANGE_JOINW column in the events_statements_current table.
+SUM_SELECT_RANGE	Sum of the SELECT_RANGE column in the events_statements_current table.
+SUM_SELECT_RANGE_CHECK	Sum of the SELECT_RANGE_CHECK column in the events_statements_current table.
+SUM_SELECT_SCAN	Sum of the SELECT_SCAN column in the events_statements_current table.
+SUM_SORT_MERGE_PASSES	Sum of the SORT_MERGE_PASSES column in the events_statements_current table.
+SUM_SORT_RANGE	Sum of the SORT_RANGE column in the events_statements_current table.
+SUM_SORT_ROWS	Sum of the SORT_ROWS column in the events_statements_current table.
+SUM_SORT_SCAN	Sum of the SORT_SCAN column in the events_statements_current table.
+SUM_NO_INDEX_USED	Sum of the NO_INDEX_USED column in the events_statements_current table.
+SUM_NO_GOOD_INDEX_USED	Sum of the NO_GOOD_INDEX_USED column in the events_statements_current table.

mysql-test/suite/perfschema/r/dml_esms_by_thread_by_event_name.result

@@ -24,3 +24,36 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_statements_summary_by_thread_by_event_name WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'events_statements_summary_by_thread_by_event_name'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_statements_summary_by_thread_by_event_name';
+column_name	column_comment
+THREAD_ID	Thread associated with the event. Together with EVENT_NAME uniquely identifies the row.
+EVENT_NAME	Event name. Used together with THREAD_ID for grouping events.
+COUNT_STAR	Number of summarized events
+SUM_TIMER_WAIT	Total wait time of the summarized events that are timed.
+MIN_TIMER_WAIT	Minimum wait time of the summarized events that are timed.
+AVG_TIMER_WAIT	Average wait time of the summarized events that are timed.
+MAX_TIMER_WAIT	Maximum wait time of the summarized events that are timed.
+SUM_LOCK_TIME	Sum of the LOCK_TIME column in the events_statements_current table.
+SUM_ERRORS	Sum of the ERRORS column in the events_statements_current table.
+SUM_WARNINGS	Sum of the WARNINGS column in the events_statements_current table.
+SUM_ROWS_AFFECTED	Sum of the ROWS_AFFECTED column in the events_statements_current table.
+SUM_ROWS_SENT	Sum of the ROWS_SENT column in the events_statements_current table.
+SUM_ROWS_EXAMINED	Sum of the ROWS_EXAMINED column in the events_statements_current table.
+SUM_CREATED_TMP_DISK_TABLES	Sum of the CREATED_TMP_DISK_TABLES column in the events_statements_current table.
+SUM_CREATED_TMP_TABLES	Sum of the CREATED_TMP_TABLES column in the events_statements_current table.
+SUM_SELECT_FULL_JOIN	Sum of the SELECT_FULL_JOIN column in the events_statements_current table.
+SUM_SELECT_FULL_RANGE_JOIN	Sum of the SELECT_FULL_RANGE_JOIN column in the events_statements_current table.
+SUM_SELECT_RANGE	Sum of the SELECT_RANGE column in the events_statements_current table.
+SUM_SELECT_RANGE_CHECK	Sum of the SELECT_RANGE_CHECK column in the events_statements_current table.
+SUM_SELECT_SCAN	Sum of the SELECT_SCAN column in the events_statements_current table.
+SUM_SORT_MERGE_PASSES	Sum of the SORT_MERGE_PASSES column in the events_statements_current table.
+SUM_SORT_RANGE	Sum of the SORT_RANGE column in the events_statements_current table.
+SUM_SORT_ROWS	Sum of the SORT_ROWS column in the events_statements_current table.
+SUM_SORT_SCAN	Sum of the SORT_SCAN column in the events_statements_current table.
+SUM_NO_INDEX_USED	Sum of the NO_INDEX_USED column in the events_statements_current table.
+SUM_NO_GOOD_INDEX_USED	Sum of the NO_GOOD_INDEX_USED column in the events_statements_current table.

mysql-test/suite/perfschema/r/dml_esms_by_user_by_event_name.result

@@ -24,3 +24,36 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_statements_summary_by_user_by_event_name WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'events_statements_summary_by_user_by_event_name'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_statements_summary_by_user_by_event_name';
+column_name	column_comment
+USER	User. Used together with EVENT_NAME for grouping events.
+EVENT_NAME	Event name. Used together with USER for grouping events.
+COUNT_STAR	Number of summarized events
+SUM_TIMER_WAIT	Total wait time of the summarized events that are timed.
+MIN_TIMER_WAIT	Minimum wait time of the summarized events that are timed.
+AVG_TIMER_WAIT	Average wait time of the summarized events that are timed.
+MAX_TIMER_WAIT	Maximum wait time of the summarized events that are timed.
+SUM_LOCK_TIME	Sum of the LOCK_TIME column in the events_statements_current table.
+SUM_ERRORS	Sum of the ERRORS column in the events_statements_current table.
+SUM_WARNINGS	Sum of the WARNINGS column in the events_statements_current table.
+SUM_ROWS_AFFECTED	Sum of the ROWS_AFFECTED column in the events_statements_current table.
+SUM_ROWS_SENT	Sum of the ROWS_SENT column in the events_statements_current table.
+SUM_ROWS_EXAMINED	Sum of the ROWS_EXAMINED column in the events_statements_current table.
+SUM_CREATED_TMP_DISK_TABLES	Sum of the CREATED_TMP_DISK_TABLES column in the events_statements_current table.
+SUM_CREATED_TMP_TABLES	Sum of the CREATED_TMP_TABLES column in the events_statements_current table.
+SUM_SELECT_FULL_JOIN	Sum of the SELECT_FULL_JOIN column in the events_statements_current table.
+SUM_SELECT_FULL_RANGE_JOIN	Sum of the SELECT_FULL_RANGE_JOIN column in the events_statements_current table.
+SUM_SELECT_RANGE	Sum of the SELECT_RANGE column in the events_statements_current table.
+SUM_SELECT_RANGE_CHECK	Sum of the SELECT_RANGE_CHECK column in the events_statements_current table.
+SUM_SELECT_SCAN	Sum of the SELECT_SCAN column in the events_statements_current table.
+SUM_SORT_MERGE_PASSES	Sum of the SORT_MERGE_PASSES column in the events_statements_current table.
+SUM_SORT_RANGE	Sum of the SORT_RANGE column in the events_statements_current table.
+SUM_SORT_ROWS	Sum of the SORT_ROWS column in the events_statements_current table.
+SUM_SORT_SCAN	Sum of the SORT_SCAN column in the events_statements_current table.
+SUM_NO_INDEX_USED	Sum of the NO_INDEX_USED column in the events_statements_current table.
+SUM_NO_GOOD_INDEX_USED	Sum of the NO_GOOD_INDEX_USED column in the events_statements_current table.

mysql-test/suite/perfschema/r/dml_esms_global_by_event_name.result

@@ -23,3 +23,35 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_statements_summary_global_by_event_name WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'events_statements_summary_global_by_event_name'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_statements_summary_global_by_event_name';
+column_name	column_comment
+EVENT_NAME	Event name.
+COUNT_STAR	Number of summarized events
+SUM_TIMER_WAIT	Total wait time of the summarized events that are timed.
+MIN_TIMER_WAIT	Minimum wait time of the summarized events that are timed.
+AVG_TIMER_WAIT	Average wait time of the summarized events that are timed.
+MAX_TIMER_WAIT	Maximum wait time of the summarized events that are timed.
+SUM_LOCK_TIME	Sum of the LOCK_TIME column in the events_statements_current table.
+SUM_ERRORS	Sum of the ERRORS column in the events_statements_current table.
+SUM_WARNINGS	Sum of the WARNINGS column in the events_statements_current table.
+SUM_ROWS_AFFECTED	Sum of the ROWS_AFFECTED column in the events_statements_current table.
+SUM_ROWS_SENT	Sum of the ROWS_SENT column in the events_statements_current table.
+SUM_ROWS_EXAMINED	Sum of the ROWS_EXAMINED column in the events_statements_current table.
+SUM_CREATED_TMP_DISK_TABLES	Sum of the CREATED_TMP_DISK_TABLES column in the events_statements_current table.
+SUM_CREATED_TMP_TABLES	Sum of the CREATED_TMP_TABLES column in the events_statements_current table.
+SUM_SELECT_FULL_JOIN	Sum of the SELECT_FULL_JOIN column in the events_statements_current table.
+SUM_SELECT_FULL_RANGE_JOIN	Sum of the SELECT_FULL_RANGE_JOIN column in the events_statements_current table.
+SUM_SELECT_RANGE	Sum of the SELECT_RANGE column in the events_statements_current table.
+SUM_SELECT_RANGE_CHECK	Sum of the SELECT_RANGE_CHECK column in the events_statements_current table.
+SUM_SELECT_SCAN	Sum of the SELECT_SCAN column in the events_statements_current table.
+SUM_SORT_MERGE_PASSES	Sum of the SORT_MERGE_PASSES column in the events_statements_current table.
+SUM_SORT_RANGE	Sum of the SORT_RANGE column in the events_statements_current table.
+SUM_SORT_ROWS	Sum of the SORT_ROWS column in the events_statements_current table.
+SUM_SORT_SCAN	Sum of the SORT_SCAN column in the events_statements_current table.
+SUM_NO_INDEX_USED	Sum of the NO_INDEX_USED column in the events_statements_current table.
+SUM_NO_GOOD_INDEX_USED	Sum of the NO_GOOD_INDEX_USED column in the events_statements_current table.

mysql-test/suite/perfschema/r/dml_events_stages_current.result

@@ -23,3 +23,20 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_stages_current WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'events_stages_current'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_stages_current';
+column_name	column_comment
+THREAD_ID	Thread associated with the event. Together with EVENT_ID uniquely identifies the row.
+EVENT_ID	Thread's current event number at the start of the event. Together with THREAD_ID uniquely identifies the row.
+END_EVENT_ID	NULL when the event starts, set to the thread's current event number at the end of the event.
+EVENT_NAME	Event instrument name and a NAME from the setup_instruments table
+SOURCE	Name and line number of the source file containing the instrumented code that produced the event.
+TIMER_START	Value in picoseconds when the event timing started or NULL if timing is not collected.
+TIMER_END	Value in picoseconds when the event timing ended, or NULL if the event has not ended or timing is not collected.
+TIMER_WAIT	Value in picoseconds of the event's duration or NULL if the event has not ended or timing is not collected.
+NESTING_EVENT_ID	EVENT_ID of event within which this event nests.
+NESTING_EVENT_TYPE	Nesting event type. Either statement, stage or wait.

mysql-test/suite/perfschema/r/dml_events_stages_history.result

@@ -27,3 +27,20 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_stages_history WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'events_stages_history'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_stages_history';
+column_name	column_comment
+THREAD_ID	Thread associated with the event. Together with EVENT_ID uniquely identifies the row.
+EVENT_ID	Thread's current event number at the start of the event. Together with THREAD_ID uniquely identifies the row.
+END_EVENT_ID	NULL when the event starts, set to the thread's current event number at the end of the event.
+EVENT_NAME	Event instrument name and a NAME from the setup_instruments table
+SOURCE	Name and line number of the source file containing the instrumented code that produced the event.
+TIMER_START	Value in picoseconds when the event timing started or NULL if timing is not collected.
+TIMER_END	Value in picoseconds when the event timing ended, or NULL if the event has not ended or timing is not collected.
+TIMER_WAIT	Value in picoseconds of the event's duration or NULL if the event has not ended or timing is not collected.
+NESTING_EVENT_ID	EVENT_ID of event within which this event nests.
+NESTING_EVENT_TYPE	Nesting event type. Either statement, stage or wait.

mysql-test/suite/perfschema/r/dml_events_stages_history_long.result

@@ -27,3 +27,20 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_stages_history_long WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'events_stages_history_long'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_stages_history_long';
+column_name	column_comment
+THREAD_ID	Thread associated with the event. Together with EVENT_ID uniquely identifies the row.
+EVENT_ID	Thread's current event number at the start of the event. Together with THREAD_ID uniquely identifies the row.
+END_EVENT_ID	NULL when the event starts, set to the thread's current event number at the end of the event.
+EVENT_NAME	Event instrument name and a NAME from the setup_instruments table
+SOURCE	Name and line number of the source file containing the instrumented code that produced the event.
+TIMER_START	Value in picoseconds when the event timing started or NULL if timing is not collected.
+TIMER_END	Value in picoseconds when the event timing ended, or NULL if the event has not ended or timing is not collected.
+TIMER_WAIT	Value in picoseconds of the event's duration or NULL if the event has not ended or timing is not collected.
+NESTING_EVENT_ID	EVENT_ID of event within which this event nests.
+NESTING_EVENT_TYPE	Nesting event type. Either statement, stage or wait.

mysql-test/suite/perfschema/r/dml_events_statements_current.result

@@ -23,3 +23,50 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_statements_current WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'events_statements_current'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_statements_current';
+column_name	column_comment
+THREAD_ID	Thread associated with the event. Together with EVENT_ID uniquely identifies the row.
+EVENT_ID	Thread's current event number at the start of the event. Together with THREAD_ID uniquely identifies the row.
+END_EVENT_ID	NULL when the event starts, set to the thread's current event number at the end of the event.
+EVENT_NAME	Event instrument name and a NAME from the setup_instruments table
+SOURCE	Name and line number of the source file containing the instrumented code that produced the event.
+TIMER_START	Value in picoseconds when the event timing started or NULL if timing is not collected.
+TIMER_END	Value in picoseconds when the event timing ended, or NULL if the event has not ended or timing is not collected.
+TIMER_WAIT	Value in picoseconds of the event's duration or NULL if the event has not ended or timing is not collected.
+LOCK_TIME	Time in picoseconds spent waiting for locks. The time is calculated in microseconds but stored in picoseconds for compatibility with other timings.
+SQL_TEXT	The SQL statement, or NULL if the command is not associated with an SQL statement.
+DIGEST	Statement digest.
+DIGEST_TEXT	Statement digest text.
+CURRENT_SCHEMA	Statement's default database for the statement, or NULL if there was none.
+OBJECT_TYPE	Reserved, currently NULL
+OBJECT_SCHEMA	Reserved, currently NULL
+OBJECT_NAME	Reserved, currently NULL
+OBJECT_INSTANCE_BEGIN	Address in memory of the statement object.
+MYSQL_ERRNO	Error code. See MariaDB Error Codes for a full list.
+RETURNED_SQLSTATE	The SQLSTATE value.
+MESSAGE_TEXT	Statement error message. See MariaDB Error Codes.
+ERRORS	0 if SQLSTATE signifies completion (starting with 00) or warning (01), otherwise 1.
+WARNINGS	Number of warnings from the diagnostics area.
+ROWS_AFFECTED	Number of rows affected the statement affected.
+ROWS_SENT	Number of rows returned.
+ROWS_EXAMINED	Number of rows read during the statement's execution.
+CREATED_TMP_DISK_TABLES	Number of on-disk temp tables created by the statement.
+CREATED_TMP_TABLES	Number of temp tables created by the statement.
+SELECT_FULL_JOIN	Number of joins performed by the statement which did not use an index.
+SELECT_FULL_RANGE_JOIN	Number of joins performed by the statement which used a range search of the first table.
+SELECT_RANGE	Number of joins performed by the statement which used a range of the first table.
+SELECT_RANGE_CHECK	Number of joins without keys performed by the statement that check for key usage after each row.
+SELECT_SCAN	Number of joins performed by the statement which used a full scan of the first table.
+SORT_MERGE_PASSES	Number of merge passes by the sort algorithm performed by the statement. If too high, you may need to increase the sort_buffer_size.
+SORT_RANGE	Number of sorts performed by the statement which used a range.
+SORT_ROWS	Number of rows sorted by the statement.
+SORT_SCAN	Number of sorts performed by the statement which used a full table scan.
+NO_INDEX_USED	0 if the statement performed a table scan with an index, 1 if without an index.
+NO_GOOD_INDEX_USED	0 if a good index was found for the statement, 1 if no good index was found. See the Range checked for each record description in the EXPLAIN article.
+NESTING_EVENT_ID	Reserved, currently NULL.
+NESTING_EVENT_TYPE	Reserved, currently NULL.

mysql-test/suite/perfschema/r/dml_events_statements_history.result

@@ -27,3 +27,50 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_statements_history WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'events_statements_history'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_statements_history';
+column_name	column_comment
+THREAD_ID	Thread associated with the event. Together with EVENT_ID uniquely identifies the row.
+EVENT_ID	Thread's current event number at the start of the event. Together with THREAD_ID uniquely identifies the row.
+END_EVENT_ID	NULL when the event starts, set to the thread's current event number at the end of the event.
+EVENT_NAME	Event instrument name and a NAME from the setup_instruments table
+SOURCE	Name and line number of the source file containing the instrumented code that produced the event.
+TIMER_START	Value in picoseconds when the event timing started or NULL if timing is not collected.
+TIMER_END	Value in picoseconds when the event timing ended, or NULL if the event has not ended or timing is not collected.
+TIMER_WAIT	Value in picoseconds of the event's duration or NULL if the event has not ended or timing is not collected.
+LOCK_TIME	Time in picoseconds spent waiting for locks. The time is calculated in microseconds but stored in picoseconds for compatibility with other timings.
+SQL_TEXT	The SQL statement, or NULL if the command is not associated with an SQL statement.
+DIGEST	Statement digest.
+DIGEST_TEXT	Statement digest text.
+CURRENT_SCHEMA	Statement's default database for the statement, or NULL if there was none.
+OBJECT_TYPE	Reserved, currently NULL
+OBJECT_SCHEMA	Reserved, currently NULL
+OBJECT_NAME	Reserved, currently NULL
+OBJECT_INSTANCE_BEGIN	Address in memory of the statement object.
+MYSQL_ERRNO	Error code. See MariaDB Error Codes for a full list.
+RETURNED_SQLSTATE	The SQLSTATE value.
+MESSAGE_TEXT	Statement error message. See MariaDB Error Codes.
+ERRORS	0 if SQLSTATE signifies completion (starting with 00) or warning (01), otherwise 1.
+WARNINGS	Number of warnings from the diagnostics area.
+ROWS_AFFECTED	Number of rows affected the statement affected.
+ROWS_SENT	Number of rows returned.
+ROWS_EXAMINED	Number of rows read during the statement's execution.
+CREATED_TMP_DISK_TABLES	Number of on-disk temp tables created by the statement.
+CREATED_TMP_TABLES	Number of temp tables created by the statement.
+SELECT_FULL_JOIN	Number of joins performed by the statement which did not use an index.
+SELECT_FULL_RANGE_JOIN	Number of joins performed by the statement which used a range search of the first table.
+SELECT_RANGE	Number of joins performed by the statement which used a range of the first table.
+SELECT_RANGE_CHECK	Number of joins without keys performed by the statement that check for key usage after each row.
+SELECT_SCAN	Number of joins performed by the statement which used a full scan of the first table.
+SORT_MERGE_PASSES	Number of merge passes by the sort algorithm performed by the statement. If too high, you may need to increase the sort_buffer_size.
+SORT_RANGE	Number of sorts performed by the statement which used a range.
+SORT_ROWS	Number of rows sorted by the statement.
+SORT_SCAN	Number of sorts performed by the statement which used a full table scan.
+NO_INDEX_USED	0 if the statement performed a table scan with an index, 1 if without an index.
+NO_GOOD_INDEX_USED	0 if a good index was found for the statement, 1 if no good index was found. See the Range checked for each record description in the EXPLAIN article.
+NESTING_EVENT_ID	Reserved, currently NULL.
+NESTING_EVENT_TYPE	Reserved, currently NULL.

mysql-test/suite/perfschema/r/dml_events_statements_history_long.result

@@ -27,3 +27,50 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_statements_history_long WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'events_statements_history_long'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_statements_history_long';
+column_name	column_comment
+THREAD_ID	Thread associated with the event. Together with EVENT_ID uniquely identifies the row.
+EVENT_ID	Thread's current event number at the start of the event. Together with THREAD_ID uniquely identifies the row.
+END_EVENT_ID	NULL when the event starts, set to the thread's current event number at the end of the event.
+EVENT_NAME	Event instrument name and a NAME from the setup_instruments table
+SOURCE	Name and line number of the source file containing the instrumented code that produced the event.
+TIMER_START	Value in picoseconds when the event timing started or NULL if timing is not collected.
+TIMER_END	Value in picoseconds when the event timing ended, or NULL if the event has not ended or timing is not collected.
+TIMER_WAIT	Value in picoseconds of the event's duration or NULL if the event has not ended or timing is not collected.
+LOCK_TIME	Time in picoseconds spent waiting for locks. The time is calculated in microseconds but stored in picoseconds for compatibility with other timings.
+SQL_TEXT	The SQL statement, or NULL if the command is not associated with an SQL statement.
+DIGEST	Statement digest.
+DIGEST_TEXT	Statement digest text.
+CURRENT_SCHEMA	Statement's default database for the statement, or NULL if there was none.
+OBJECT_TYPE	Reserved, currently NULL
+OBJECT_SCHEMA	Reserved, currently NULL
+OBJECT_NAME	Reserved, currently NULL
+OBJECT_INSTANCE_BEGIN	Address in memory of the statement object.
+MYSQL_ERRNO	Error code. See MariaDB Error Codes for a full list.
+RETURNED_SQLSTATE	The SQLSTATE value.
+MESSAGE_TEXT	Statement error message. See MariaDB Error Codes.
+ERRORS	0 if SQLSTATE signifies completion (starting with 00) or warning (01), otherwise 1.
+WARNINGS	Number of warnings from the diagnostics area.
+ROWS_AFFECTED	Number of rows affected the statement affected.
+ROWS_SENT	Number of rows returned.
+ROWS_EXAMINED	Number of rows read during the statement's execution.
+CREATED_TMP_DISK_TABLES	Number of on-disk temp tables created by the statement.
+CREATED_TMP_TABLES	Number of temp tables created by the statement.
+SELECT_FULL_JOIN	Number of joins performed by the statement which did not use an index.
+SELECT_FULL_RANGE_JOIN	Number of joins performed by the statement which used a range search of the first table.
+SELECT_RANGE	Number of joins performed by the statement which used a range of the first table.
+SELECT_RANGE_CHECK	Number of joins without keys performed by the statement that check for key usage after each row.
+SELECT_SCAN	Number of joins performed by the statement which used a full scan of the first table.
+SORT_MERGE_PASSES	Number of merge passes by the sort algorithm performed by the statement. If too high, you may need to increase the sort_buffer_size.
+SORT_RANGE	Number of sorts performed by the statement which used a range.
+SORT_ROWS	Number of rows sorted by the statement.
+SORT_SCAN	Number of sorts performed by the statement which used a full table scan.
+NO_INDEX_USED	0 if the statement performed a table scan with an index, 1 if without an index.
+NO_GOOD_INDEX_USED	0 if a good index was found for the statement, 1 if no good index was found. See the Range checked for each record description in the EXPLAIN article.
+NESTING_EVENT_ID	Reserved, currently NULL.
+NESTING_EVENT_TYPE	Reserved, currently NULL.

mysql-test/suite/perfschema/r/dml_events_waits_current.result

@@ -23,3 +23,29 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_waits_current WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'events_waits_current'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_waits_current';
+column_name	column_comment
+THREAD_ID	Thread associated with the event. Together with EVENT_ID uniquely identifies the row.
+EVENT_ID	Thread's current event number at the start of the event. Together with THREAD_ID uniquely identifies the row.
+END_EVENT_ID	NULL when the event starts, set to the thread's current event number at the end of the event.
+EVENT_NAME	Event instrument name and a NAME from the setup_instruments table
+SOURCE	Name and line number of the source file containing the instrumented code that produced the event.
+TIMER_START	Value in picoseconds when the event timing started or NULL if timing is not collected.
+TIMER_END	Value in picoseconds when the event timing ended, or NULL if the event has not ended or timing is not collected.
+TIMER_WAIT	Value in picoseconds of the event's duration or NULL if the event has not ended or timing is not collected.
+SPINS	Number of spin rounds for a mutex, or NULL if spin rounds are not used, or spinning is not instrumented.
+OBJECT_SCHEMA	Name of the schema that contains the table for table I/O objects, otherwise NULL for file I/O and synchronization objects.
+OBJECT_NAME	File name for file I/O objects, table name for table I/O objects, the socket's IP:PORT value for a socket object or NULL for a synchronization object.
+INDEX_NAME	Name of the index, PRIMARY for the primary key, or NULL for no index used.
+OBJECT_TYPE	FILE for a file object, TABLE or TEMPORARY TABLE for a table object, or NULL for a synchronization object.
+OBJECT_INSTANCE_BEGIN	Address in memory of the object.
+NESTING_EVENT_ID	EVENT_ID of event within which this event nests.
+NESTING_EVENT_TYPE	Nesting event type. Either statement, stage or wait.
+OPERATION	Operation type, for example read, write or lock
+NUMBER_OF_BYTES	Number of bytes that the operation read or wrote, or NULL for table I/O waits.
+FLAGS	Reserved for use in the future.

mysql-test/suite/perfschema/r/dml_events_waits_history.result

@@ -27,3 +27,29 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_waits_history WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'events_waits_history'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_waits_history';
+column_name	column_comment
+THREAD_ID	Thread associated with the event. Together with EVENT_ID uniquely identifies the row.
+EVENT_ID	Thread's current event number at the start of the event. Together with THREAD_ID uniquely identifies the row.
+END_EVENT_ID	NULL when the event starts, set to the thread's current event number at the end of the event.
+EVENT_NAME	Event instrument name and a NAME from the setup_instruments table
+SOURCE	Name and line number of the source file containing the instrumented code that produced the event.
+TIMER_START	Value in picoseconds when the event timing started or NULL if timing is not collected.
+TIMER_END	Value in picoseconds when the event timing ended, or NULL if the event has not ended or timing is not collected.
+TIMER_WAIT	Value in picoseconds of the event's duration or NULL if the event has not ended or timing is not collected.
+SPINS	Number of spin rounds for a mutex, or NULL if spin rounds are not used, or spinning is not instrumented.
+OBJECT_SCHEMA	Name of the schema that contains the table for table I/O objects, otherwise NULL for file I/O and synchronization objects.
+OBJECT_NAME	File name for file I/O objects, table name for table I/O objects, the socket's IP:PORT value for a socket object or NULL for a synchronization object.
+INDEX_NAME	Name of the index, PRIMARY for the primary key, or NULL for no index used.
+OBJECT_TYPE	FILE for a file object, TABLE or TEMPORARY TABLE for a table object, or NULL for a synchronization object.
+OBJECT_INSTANCE_BEGIN	Address in memory of the object.
+NESTING_EVENT_ID	EVENT_ID of event within which this event nests.
+NESTING_EVENT_TYPE	Nesting event type. Either statement, stage or wait.
+OPERATION	Operation type, for example read, write or lock
+NUMBER_OF_BYTES	Number of bytes that the operation read or wrote, or NULL for table I/O waits.
+FLAGS	Reserved for use in the future.

mysql-test/suite/perfschema/r/dml_events_waits_history_long.result

@@ -27,3 +27,29 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_waits_history_long WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'events_waits_history_long'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_waits_history_long';
+column_name	column_comment
+THREAD_ID	Thread associated with the event. Together with EVENT_ID uniquely identifies the row.
+EVENT_ID	Thread's current event number at the start of the event. Together with THREAD_ID uniquely identifies the row.
+END_EVENT_ID	NULL when the event starts, set to the thread's current event number at the end of the event.
+EVENT_NAME	Event instrument name and a NAME from the setup_instruments table
+SOURCE	Name and line number of the source file containing the instrumented code that produced the event.
+TIMER_START	Value in picoseconds when the event timing started or NULL if timing is not collected.
+TIMER_END	Value in picoseconds when the event timing ended, or NULL if the event has not ended or timing is not collected.
+TIMER_WAIT	Value in picoseconds of the event's duration or NULL if the event has not ended or timing is not collected.
+SPINS	Number of spin rounds for a mutex, or NULL if spin rounds are not used, or spinning is not instrumented.
+OBJECT_SCHEMA	Name of the schema that contains the table for table I/O objects, otherwise NULL for file I/O and synchronization objects.
+OBJECT_NAME	File name for file I/O objects, table name for table I/O objects, the socket's IP:PORT value for a socket object or NULL for a synchronization object.
+INDEX_NAME	Name of the index, PRIMARY for the primary key, or NULL for no index used.
+OBJECT_TYPE	FILE for a file object, TABLE or TEMPORARY TABLE for a table object, or NULL for a synchronization object.
+OBJECT_INSTANCE_BEGIN	Address in memory of the object.
+NESTING_EVENT_ID	EVENT_ID of event within which this event nests.
+NESTING_EVENT_TYPE	Nesting event type. Either statement, stage or wait.
+OPERATION	Operation type, for example read, write or lock
+NUMBER_OF_BYTES	Number of bytes that the operation read or wrote, or NULL for table I/O waits.
+FLAGS	Reserved for use in the future.

mysql-test/suite/perfschema/r/dml_ews_by_account_by_event_name.result

@@ -27,3 +27,18 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_waits_summary_by_account_by_event_name WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'events_waits_summary_by_account_by_event_name'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_waits_summary_by_account_by_event_name';
+column_name	column_comment
+USER	User. Used together with HOST and EVENT_NAME for grouping events.
+HOST	Host. Used together with USER and EVENT_NAME for grouping events.
+EVENT_NAME	Event name. Used together with USER and HOST for grouping events.
+COUNT_STAR	Number of summarized events
+SUM_TIMER_WAIT	Total wait time of the summarized events that are timed.
+MIN_TIMER_WAIT	Minimum wait time of the summarized events that are timed.
+AVG_TIMER_WAIT	Average wait time of the summarized events that are timed.
+MAX_TIMER_WAIT	Maximum wait time of the summarized events that are timed.

mysql-test/suite/perfschema/r/dml_ews_by_host_by_event_name.result

@@ -27,3 +27,17 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_waits_summary_by_host_by_event_name WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'events_waits_summary_by_host_by_event_name'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_waits_summary_by_host_by_event_name';
+column_name	column_comment
+HOST	Host. Used together with EVENT_NAME for grouping events.
+EVENT_NAME	Event name. Used together with USER and HOST for grouping events.
+COUNT_STAR	Number of summarized events
+SUM_TIMER_WAIT	Total wait time of the summarized events that are timed.
+MIN_TIMER_WAIT	Minimum wait time of the summarized events that are timed.
+AVG_TIMER_WAIT	Average wait time of the summarized events that are timed.
+MAX_TIMER_WAIT	Maximum wait time of the summarized events that are timed.

mysql-test/suite/perfschema/r/dml_ews_by_instance.result

@@ -32,3 +32,17 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_waits_summary_by_instance WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'events_waits_summary_by_instance'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_waits_summary_by_instance';
+column_name	column_comment
+EVENT_NAME	Event name. Used together with OBJECT_INSTANCE_BEGIN for grouping events.
+OBJECT_INSTANCE_BEGIN	If an instrument creates multiple instances, each instance has a unique OBJECT_INSTANCE_BEGIN value to allow for grouping by instance.
+COUNT_STAR	Number of summarized events
+SUM_TIMER_WAIT	Total wait time of the summarized events that are timed.
+MIN_TIMER_WAIT	Minimum wait time of the summarized events that are timed.
+AVG_TIMER_WAIT	Average wait time of the summarized events that are timed.
+MAX_TIMER_WAIT	Maximum wait time of the summarized events that are timed.

mysql-test/suite/perfschema/r/dml_ews_by_thread_by_event_name.result

@@ -24,3 +24,17 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_waits_summary_by_thread_by_event_name WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'events_waits_summary_by_thread_by_event_name'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_waits_summary_by_thread_by_event_name';
+column_name	column_comment
+THREAD_ID	Thread associated with the event. Together with EVENT_NAME uniquely identifies the row.
+EVENT_NAME	Event name. Used together with THREAD_ID for grouping events.
+COUNT_STAR	Number of summarized events
+SUM_TIMER_WAIT	Total wait time of the summarized events that are timed.
+MIN_TIMER_WAIT	Minimum wait time of the summarized events that are timed.
+AVG_TIMER_WAIT	Average wait time of the summarized events that are timed.
+MAX_TIMER_WAIT	Maximum wait time of the summarized events that are timed.

mysql-test/suite/perfschema/r/dml_ews_by_user_by_event_name.result

@@ -27,3 +27,17 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_waits_summary_by_user_by_event_name WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'events_waits_summary_by_user_by_event_name'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_waits_summary_by_user_by_event_name';
+column_name	column_comment
+USER	User. Used together with EVENT_NAME for grouping events.
+EVENT_NAME	Event name. Used together with USER for grouping events.
+COUNT_STAR	Number of summarized events
+SUM_TIMER_WAIT	Total wait time of the summarized events that are timed.
+MIN_TIMER_WAIT	Minimum wait time of the summarized events that are timed.
+AVG_TIMER_WAIT	Average wait time of the summarized events that are timed.
+MAX_TIMER_WAIT	Maximum wait time of the summarized events that are timed.

mysql-test/suite/perfschema/r/dml_ews_global_by_event_name.result

@@ -23,3 +23,16 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_waits_summary_global_by_event_name WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'events_waits_summary_global_by_event_name'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_waits_summary_global_by_event_name';
+column_name	column_comment
+EVENT_NAME	Event name.
+COUNT_STAR	Number of summarized events
+SUM_TIMER_WAIT	Total wait time of the summarized events that are timed.
+MIN_TIMER_WAIT	Minimum wait time of the summarized events that are timed.
+AVG_TIMER_WAIT	Average wait time of the summarized events that are timed.
+MAX_TIMER_WAIT	Maximum wait time of the summarized events that are timed.

mysql-test/suite/perfschema/r/dml_file_instances.result

@@ -18,3 +18,13 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.file_instances WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'file_instances'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='file_instances';
+column_name	column_comment
+FILE_NAME	File name.
+EVENT_NAME	Instrument name associated with the file.
+OPEN_COUNT	Open handles on the file. A value of greater than zero means that the file is currently open.

mysql-test/suite/perfschema/r/dml_fs_by_event_name.result

@@ -23,3 +23,33 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.file_summary_by_event_name WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'file_summary_by_event_name'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='file_summary_by_event_name';
+column_name	column_comment
+EVENT_NAME	Event name.
+COUNT_STAR	Number of summarized events
+SUM_TIMER_WAIT	Total wait time of the summarized events that are timed.
+MIN_TIMER_WAIT	Minimum wait time of the summarized events that are timed.
+AVG_TIMER_WAIT	Average wait time of the summarized events that are timed.
+MAX_TIMER_WAIT	Maximum wait time of the summarized events that are timed.
+COUNT_READ	Number of all read operations, including FGETS, FGETC, FREAD, and READ.
+SUM_TIMER_READ	Total wait time of all read operations that are timed.
+MIN_TIMER_READ	Minimum wait time of all read operations that are timed.
+AVG_TIMER_READ	Average wait time of all read operations that are timed.
+MAX_TIMER_READ	Maximum wait time of all read operations that are timed.
+SUM_NUMBER_OF_BYTES_READ	Bytes read by read operations.
+COUNT_WRITE	Number of all write operations, including FPUTS, FPUTC, FPRINTF, VFPRINTF, FWRITE, and PWRITE.
+SUM_TIMER_WRITE	Total wait time of all write operations that are timed.
+MIN_TIMER_WRITE	Minimum wait time of all write operations that are timed.
+AVG_TIMER_WRITE	Average wait time of all write operations that are timed.
+MAX_TIMER_WRITE	Maximum wait time of all write operations that are timed.
+SUM_NUMBER_OF_BYTES_WRITE	Bytes written by write operations.
+COUNT_MISC	Number of all miscellaneous operations not counted above, including CREATE, DELETE, OPEN, CLOSE, STREAM_OPEN, STREAM_CLOSE, SEEK, TELL, FLUSH, STAT, FSTAT, CHSIZE, RENAME, and SYNC.
+SUM_TIMER_MISC	Total wait time of all miscellaneous operations that are timed.
+MIN_TIMER_MISC	Minimum wait time of all miscellaneous operations that are timed.
+AVG_TIMER_MISC	Average wait time of all miscellaneous operations that are timed.
+MAX_TIMER_MISC	Maximum wait time of all miscellaneous operations that are timed.

mysql-test/suite/perfschema/r/dml_fs_by_instance.result

@@ -23,3 +23,35 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.file_summary_by_instance WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'file_summary_by_instance'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='file_summary_by_instance';
+column_name	column_comment
+FILE_NAME	File name.
+EVENT_NAME	Event name.
+OBJECT_INSTANCE_BEGIN	Address in memory. Together with FILE_NAME and EVENT_NAME uniquely identifies a row.
+COUNT_STAR	Number of summarized events
+SUM_TIMER_WAIT	Total wait time of the summarized events that are timed.
+MIN_TIMER_WAIT	Minimum wait time of the summarized events that are timed.
+AVG_TIMER_WAIT	Average wait time of the summarized events that are timed.
+MAX_TIMER_WAIT	Maximum wait time of the summarized events that are timed.
+COUNT_READ	Number of all read operations, including FGETS, FGETC, FREAD, and READ.
+SUM_TIMER_READ	Total wait time of all read operations that are timed.
+MIN_TIMER_READ	Minimum wait time of all read operations that are timed.
+AVG_TIMER_READ	Average wait time of all read operations that are timed.
+MAX_TIMER_READ	Maximum wait time of all read operations that are timed.
+SUM_NUMBER_OF_BYTES_READ	Bytes read by read operations.
+COUNT_WRITE	Number of all write operations, including FPUTS, FPUTC, FPRINTF, VFPRINTF, FWRITE, and PWRITE.
+SUM_TIMER_WRITE	Total wait time of all write operations that are timed.
+MIN_TIMER_WRITE	Minimum wait time of all write operations that are timed.
+AVG_TIMER_WRITE	Average wait time of all write operations that are timed.
+MAX_TIMER_WRITE	Maximum wait time of all write operations that are timed.
+SUM_NUMBER_OF_BYTES_WRITE	Bytes written by write operations.
+COUNT_MISC	Number of all miscellaneous operations not counted above, including CREATE, DELETE, OPEN, CLOSE, STREAM_OPEN, STREAM_CLOSE, SEEK, TELL, FLUSH, STAT, FSTAT, CHSIZE, RENAME, and SYNC.
+SUM_TIMER_MISC	Total wait time of all miscellaneous operations that are timed.
+MIN_TIMER_MISC	Minimum wait time of all miscellaneous operations that are timed.
+AVG_TIMER_MISC	Average wait time of all miscellaneous operations that are timed.
+MAX_TIMER_MISC	Maximum wait time of all miscellaneous operations that are timed.

mysql-test/suite/perfschema/r/dml_host_cache.result

@@ -25,3 +25,39 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.host_cache WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'host_cache'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='host_cache';
+column_name	column_comment
+IP	Client IP address.
+HOST	IP's resolved DNS host name, or NULL if unknown.
+HOST_VALIDATED	YES if the IP-to-host DNS lookup was successful, and the HOST column can be used to avoid DNS calls, or NO if unsuccessful, in which case DNS lookup is performed for each connect until either successful or a permanent error.
+SUM_CONNECT_ERRORS	Number of connection errors. Counts only protocol handshake errors for hosts that passed validation. These errors count towards max_connect_errors.
+COUNT_HOST_BLOCKED_ERRORS	Number of blocked connections because SUM_CONNECT_ERRORS exceeded the max_connect_errors system variable.
+COUNT_NAMEINFO_TRANSIENT_ERRORS	Number of transient errors during IP-to-host DNS lookups.
+COUNT_NAMEINFO_PERMANENT_ERRORS	Number of permanent errors during IP-to-host DNS lookups.
+COUNT_FORMAT_ERRORS	Number of host name format errors, for example a numeric host column.
+COUNT_ADDRINFO_TRANSIENT_ERRORS	Number of transient errors during host-to-IP reverse DNS lookups.
+COUNT_ADDRINFO_PERMANENT_ERRORS	Number of permanent errors during host-to-IP reverse DNS lookups.
+COUNT_FCRDNS_ERRORS	Number of forward-confirmed reverse DNS errors, which occur when IP-to-host DNS lookup does not match the originating IP address.
+COUNT_HOST_ACL_ERRORS	Number of errors occurring because no user from the host is permitted to log in. These attempts return error code 1130 ER_HOST_NOT_PRIVILEGED and do not proceed to username and password authentication.
+COUNT_NO_AUTH_PLUGIN_ERRORS	Number of errors due to requesting an authentication plugin that was not available. This can be due to the plugin never having been loaded, or the load attempt failing.
+COUNT_AUTH_PLUGIN_ERRORS	Number of errors reported by an authentication plugin. Plugins can increment COUNT_AUTHENTICATION_ERRORS or COUNT_HANDSHAKE_ERRORS instead, but, if specified or the error is unknown, this column is incremented.
+COUNT_HANDSHAKE_ERRORS	Number of errors detected at the wire protocol level.
+COUNT_PROXY_USER_ERRORS	Number of errors detected when a proxy user is proxied to a user that does not exist.
+COUNT_PROXY_USER_ACL_ERRORS	Number of errors detected when a proxy user is proxied to a user that exists, but the proxy user doesn't have the PROXY privilege.
+COUNT_AUTHENTICATION_ERRORS	Number of errors where authentication failed.
+COUNT_SSL_ERRORS	Number of errors due to TLS problems.
+COUNT_MAX_USER_CONNECTIONS_ERRORS	Number of errors due to the per-user quota being exceeded.
+COUNT_MAX_USER_CONNECTIONS_PER_HOUR_ERRORS	Number of errors due to the per-hour quota being exceeded.
+COUNT_DEFAULT_DATABASE_ERRORS	Number of errors due to the user not having permission to access the specified default database, or it not existing.
+COUNT_INIT_CONNECT_ERRORS	Number of errors due to statements in the init_connect system variable.
+COUNT_LOCAL_ERRORS	Number of local server errors, such as out-of-memory errors, unrelated to network, authentication, or authorization.
+COUNT_UNKNOWN_ERRORS	Number of unknown errors that cannot be allocated to another column.
+FIRST_SEEN	Timestamp of the first connection attempt by the IP.
+LAST_SEEN	Timestamp of the most recent connection attempt by the IP.
+FIRST_ERROR_SEEN	Timestamp of the first error seen from the IP.
+LAST_ERROR_SEEN	Timestamp of the most recent error seen from the IP.

mysql-test/suite/perfschema/r/dml_hosts.result

@@ -23,3 +23,13 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.hosts WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'hosts'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='hosts';
+column_name	column_comment
+HOST	Host name used by the client to connect, NULL for internal threads or user sessions that failed to authenticate.
+CURRENT_CONNECTIONS	Current number of the host's connections.
+TOTAL_CONNECTIONS	Total number of the host's connections

mysql-test/suite/perfschema/r/dml_mutex_instances.result

@@ -18,3 +18,13 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.mutex_instances WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'mutex_instances'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='mutex_instances';
+column_name	column_comment
+NAME	Instrument name associated with the mutex.
+OBJECT_INSTANCE_BEGIN	Memory address of the instrumented mutex.
+LOCKED_BY_THREAD_ID	The THREAD_ID of the locking thread if a thread has a mutex locked, otherwise NULL.

mysql-test/suite/perfschema/r/dml_os_global_by_type.result

@@ -43,3 +43,18 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.objects_summary_global_by_type WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'objects_summary_global_by_type'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='objects_summary_global_by_type';
+column_name	column_comment
+OBJECT_TYPE	Groups records together with OBJECT_SCHEMA and OBJECT_NAME.
+OBJECT_SCHEMA	Groups records together with OBJECT_TYPE and OBJECT_NAME.
+OBJECT_NAME	Groups records together with OBJECT_SCHEMA and OBJECT_TYPE.
+COUNT_STAR	Number of summarized events
+SUM_TIMER_WAIT	Total wait time of the summarized events that are timed.
+MIN_TIMER_WAIT	Minimum wait time of the summarized events that are timed.
+AVG_TIMER_WAIT	Average wait time of the summarized events that are timed.
+MAX_TIMER_WAIT	Maximum wait time of the summarized events that are timed.

mysql-test/suite/perfschema/r/dml_performance_timers.result

@@ -27,3 +27,14 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.performance_timers WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'performance_timers'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='performance_timers';
+column_name	column_comment
+TIMER_NAME	Time name, used in the setup_timers table.
+TIMER_FREQUENCY	Number of timer units per second. Dependent on the processor speed.
+TIMER_RESOLUTION	Number of timer units by which timed values increase each time.
+TIMER_OVERHEAD	Minimum timer overhead, determined during initialization by calling the timer 20 times and selecting the smallest value. Total overhead will be at least double this, as the timer is called at the beginning and end of each timed event.

mysql-test/suite/perfschema/r/dml_rwlock_instances.result

@@ -18,3 +18,14 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.rwlock_instances WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'rwlock_instances'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='rwlock_instances';
+column_name	column_comment
+NAME	Instrument name associated with the read write lock
+OBJECT_INSTANCE_BEGIN	Address in memory of the instrumented lock
+WRITE_LOCKED_BY_THREAD_ID	THREAD_ID of the locking thread if locked in write (exclusive) mode, otherwise NULL.
+READ_LOCKED_BY_COUNT	Count of current read locks held

mysql-test/suite/perfschema/r/dml_session_account_connect_attrs.result

@@ -23,3 +23,14 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.session_account_connect_attrs WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'session_account_connect_attrs'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='session_account_connect_attrs';
+column_name	column_comment
+PROCESSLIST_ID	Session connection identifier.
+ATTR_NAME	Attribute name.
+ATTR_VALUE	Attribute value.
+ORDINAL_POSITION	Order in which attribute was added to the connection attributes.

mysql-test/suite/perfschema/r/dml_session_connect_attrs.result

@@ -23,3 +23,14 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.session_connect_attrs WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'session_connect_attrs'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='session_connect_attrs';
+column_name	column_comment
+PROCESSLIST_ID	Session connection identifier.
+ATTR_NAME	Attribute name.
+ATTR_VALUE	Attribute value.
+ORDINAL_POSITION	Order in which attribute was added to the connection attributes.

mysql-test/suite/perfschema/r/dml_setup_actors.result

@@ -58,3 +58,13 @@ truncate table performance_schema.setup_actors;
 insert into performance_schema.setup_actors
 select * from test.setup_actors;
 drop table test.setup_actors;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='setup_actors';
+column_name	column_comment
+HOST	Host name, either a literal, or the % wildcard representing any host.
+USER	User name, either a literal or the % wildcard representing any name.
+ROLE	Unused

mysql-test/suite/perfschema/r/dml_setup_consumers.result

@@ -51,3 +51,12 @@ LOCK TABLES performance_schema.setup_consumers READ;
 UNLOCK TABLES;
 LOCK TABLES performance_schema.setup_consumers WRITE;
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='setup_consumers';
+column_name	column_comment
+NAME	Consumer name
+ENABLED	YES or NO for whether or not the consumer is enabled. You can modify this column to ensure that event information is added, or is not added.

mysql-test/suite/perfschema/r/dml_setup_instruments.result

@@ -80,3 +80,13 @@ UNLOCK TABLES;
 
 UPDATE performance_schema.setup_instruments SET timed='NO'
 ORDER BY RAND();
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='setup_instruments';
+column_name	column_comment
+NAME	Instrument name
+ENABLED	Whether or not the instrument is enabled. It can be disabled, and the instrument will produce no events.
+TIMED	Whether or not the instrument is timed. It can be set, but if disabled, events produced by the instrument will have NULL values for the corresponding TIMER_START, TIMER_END, and TIMER_WAIT values.

mysql-test/suite/perfschema/r/dml_setup_objects.result

@@ -68,3 +68,15 @@ truncate table performance_schema.setup_objects;
 insert into performance_schema.setup_objects
 select * from test.setup_objects;
 drop table test.setup_objects;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='setup_objects';
+column_name	column_comment
+OBJECT_TYPE	Type of object to instrument. Currently, only TABLE, for base table.
+OBJECT_SCHEMA	Schema containing the object, either the literal or % for any schema.
+OBJECT_NAME	Name of the instrumented object, either the literal or % for any object.
+ENABLED	Whether the object's events are instrumented or not. Can be disabled, in which case monitoring is not enabled for those objects.
+TIMED	Whether the object's events are timed or not. Can be modified.

mysql-test/suite/perfschema/r/dml_setup_timers.result

@@ -59,3 +59,12 @@ idle	MICROSECOND
 wait	CYCLE
 stage	NANOSECOND
 statement	NANOSECOND
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='setup_timers';
+column_name	column_comment
+NAME	Type of instrument the timer is used for.
+TIMER_NAME	Timer applying to the instrument type. Can be modified.

mysql-test/suite/perfschema/r/dml_socket_instances.result

@@ -18,3 +18,17 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.socket_instances WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'socket_instances'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='socket_instances';
+column_name	column_comment
+EVENT_NAME	NAME from the setup_instruments table, and the name of the wait/io/socket/* instrument that produced the event.
+OBJECT_INSTANCE_BEGIN	Memory address of the object.
+THREAD_ID	Thread identifier that the server assigns to each socket.
+SOCKET_ID	The socket's internal file handle.
+IP	Client IP address. Blank for Unix socket file, otherwise an IPv4 or IPv6 address. Together with the PORT identifies the connection.
+PORT	TCP/IP port number, from 0 to 65535. Together with the IP identifies the connection.
+STATE	Socket status, either IDLE if waiting to receive a request from a client, or ACTIVE

mysql-test/suite/perfschema/r/dml_socket_summary_by_event_name.result

@@ -24,3 +24,33 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.socket_summary_by_event_name WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'socket_summary_by_event_name'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='socket_summary_by_event_name';
+column_name	column_comment
+EVENT_NAME	Socket instrument.
+COUNT_STAR	Number of summarized events
+SUM_TIMER_WAIT	Total wait time of the summarized events that are timed.
+MIN_TIMER_WAIT	Minimum wait time of the summarized events that are timed.
+AVG_TIMER_WAIT	Average wait time of the summarized events that are timed.
+MAX_TIMER_WAIT	Maximum wait time of the summarized events that are timed.
+COUNT_READ	Number of all read operations, including RECV, RECVFROM, and RECVMSG.
+SUM_TIMER_READ	Total wait time of all read operations that are timed.
+MIN_TIMER_READ	Minimum wait time of all read operations that are timed.
+AVG_TIMER_READ	Average wait time of all read operations that are timed.
+MAX_TIMER_READ	Maximum wait time of all read operations that are timed.
+SUM_NUMBER_OF_BYTES_READ	Bytes read by read operations.
+COUNT_WRITE	Number of all write operations, including SEND, SENDTO, and SENDMSG.
+SUM_TIMER_WRITE	Total wait time of all write operations that are timed.
+MIN_TIMER_WRITE	Minimum wait time of all write operations that are timed.
+AVG_TIMER_WRITE	Average wait time of all write operations that are timed.
+MAX_TIMER_WRITE	Maximum wait time of all write operations that are timed.
+SUM_NUMBER_OF_BYTES_WRITE	Bytes written by write operations.
+COUNT_MISC	Number of all miscellaneous operations not counted above, including CONNECT, LISTEN, ACCEPT, CLOSE, and SHUTDOWN.
+SUM_TIMER_MISC	Total wait time of all miscellaneous operations that are timed.
+MIN_TIMER_MISC	Minimum wait time of all miscellaneous operations that are timed.
+AVG_TIMER_MISC	Average wait time of all miscellaneous operations that are timed.
+MAX_TIMER_MISC	Maximum wait time of all miscellaneous operations that are timed.

mysql-test/suite/perfschema/r/dml_socket_summary_by_instance.result

@@ -24,3 +24,34 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.socket_summary_by_instance WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'socket_summary_by_instance'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='socket_summary_by_instance';
+column_name	column_comment
+EVENT_NAME	Socket instrument.
+OBJECT_INSTANCE_BEGIN	Address in memory.
+COUNT_STAR	Number of summarized events
+SUM_TIMER_WAIT	Total wait time of the summarized events that are timed.
+MIN_TIMER_WAIT	Minimum wait time of the summarized events that are timed.
+AVG_TIMER_WAIT	Average wait time of the summarized events that are timed.
+MAX_TIMER_WAIT	Maximum wait time of the summarized events that are timed.
+COUNT_READ	Number of all read operations, including RECV, RECVFROM, and RECVMSG.
+SUM_TIMER_READ	Total wait time of all read operations that are timed.
+MIN_TIMER_READ	Minimum wait time of all read operations that are timed.
+AVG_TIMER_READ	Average wait time of all read operations that are timed.
+MAX_TIMER_READ	Maximum wait time of all read operations that are timed.
+SUM_NUMBER_OF_BYTES_READ	Bytes read by read operations.
+COUNT_WRITE	Number of all write operations, including SEND, SENDTO, and SENDMSG.
+SUM_TIMER_WRITE	Total wait time of all write operations that are timed.
+MIN_TIMER_WRITE	Minimum wait time of all write operations that are timed.
+AVG_TIMER_WRITE	Average wait time of all write operations that are timed.
+MAX_TIMER_WRITE	Maximum wait time of all write operations that are timed.
+SUM_NUMBER_OF_BYTES_WRITE	Bytes written by write operations.
+COUNT_MISC	Number of all miscellaneous operations not counted above, including CONNECT, LISTEN, ACCEPT, CLOSE, and SHUTDOWN.
+SUM_TIMER_MISC	Total wait time of all miscellaneous operations that are timed.
+MIN_TIMER_MISC	Minimum wait time of all miscellaneous operations that are timed.
+AVG_TIMER_MISC	Average wait time of all miscellaneous operations that are timed.
+MAX_TIMER_MISC	Maximum wait time of all miscellaneous operations that are timed.

mysql-test/suite/perfschema/r/dml_threads.result

@@ -32,3 +32,24 @@ LOCK TABLES performance_schema.threads READ;
 UNLOCK TABLES;
 LOCK TABLES performance_schema.threads WRITE;
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='threads';
+column_name	column_comment
+THREAD_ID	A unique thread identifier.
+NAME	Name associated with the server's thread instrumentation code, for example thread/sql/main for the server's main() function, and thread/sql/one_connection for a user connection.
+TYPE	FOREGROUND or BACKGROUND, depending on the thread type. User connection threads are FOREGROUND, internal server threads are BACKGROUND.
+PROCESSLIST_ID	The PROCESSLIST.ID value for threads displayed in the INFORMATION_SCHEMA.PROCESSLIST table, or 0 for background threads. Also corresponds with the CONNECTION_ID() return value for the thread.
+PROCESSLIST_USER	Foreground thread user, or NULL for a background thread.
+PROCESSLIST_HOST	Foreground thread host, or NULL for a background thread.
+PROCESSLIST_DB	Thread's default database, or NULL if none exists.
+PROCESSLIST_COMMAND	Type of command executed by the thread. These correspond to the the COM_xxx client/server protocol commands, and the Com_xxx status variables. See Thread Command Values.
+PROCESSLIST_TIME	Time in seconds the thread has been in its current state.
+PROCESSLIST_STATE	Action, event or state indicating what the thread is doing.
+PROCESSLIST_INFO	Statement being executed by the thread, or NULL if a statement is not being executed. If a statement results in calling other statements, such as for a stored procedure, the innermost statement from the stored procedure is shown here.
+PARENT_THREAD_ID	THREAD_ID of the parent thread, if any. Subthreads can for example be spawned as a result of INSERT DELAYED statements.
+ROLE	Unused.
+INSTRUMENTED	YES or NO for Whether the thread is instrumented or not. For foreground threads, the initial value is determined by whether there's a user/host match in the setup_actors table. Subthreads are again matched, while for background threads, this will be set to YES by default. To monitor events that the thread executes, INSTRUMENTED must be YES and the thread_instrumentation consumer in the setup_consumers table must also be YES.

mysql-test/suite/perfschema/r/dml_tiws_by_index_usage.result

@@ -24,3 +24,49 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.table_io_waits_summary_by_index_usage WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'table_io_waits_summary_by_index_usage'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='table_io_waits_summary_by_index_usage';
+column_name	column_comment
+OBJECT_TYPE	TABLE in the case of all indexes.
+OBJECT_SCHEMA	Schema name.
+OBJECT_NAME	Table name.
+INDEX_NAME	Index name, or PRIMARY for the primary index, NULL for no index (inserts are counted in this case).
+COUNT_STAR	Number of summarized events and the sum of the x_READ and x_WRITE columns.
+SUM_TIMER_WAIT	Total wait time of the summarized events that are timed.
+MIN_TIMER_WAIT	Minimum wait time of the summarized events that are timed.
+AVG_TIMER_WAIT	Average wait time of the summarized events that are timed.
+MAX_TIMER_WAIT	Maximum wait time of the summarized events that are timed.
+COUNT_READ	Number of all read operations, and the sum of the equivalent x_FETCH columns.
+SUM_TIMER_READ	Total wait time of all read operations that are timed.
+MIN_TIMER_READ	Minimum wait time of all read operations that are timed.
+AVG_TIMER_READ	Average wait time of all read operations that are timed.
+MAX_TIMER_READ	Maximum wait time of all read operations that are timed.
+COUNT_WRITE	Number of all write operations, and the sum of the equivalent x_INSERT, x_UPDATE and x_DELETE columns.
+SUM_TIMER_WRITE	Total wait time of all write operations that are timed.
+MIN_TIMER_WRITE	Minimum wait time of all write operations that are timed.
+AVG_TIMER_WRITE	Average wait time of all write operations that are timed.
+MAX_TIMER_WRITE	Maximum wait time of all write operations that are timed.
+COUNT_FETCH	Number of all fetch operations.
+SUM_TIMER_FETCH	Total wait time of all fetch operations that are timed.
+MIN_TIMER_FETCH	Minimum wait time of all fetch operations that are timed.
+AVG_TIMER_FETCH	Average wait time of all fetch operations that are timed.
+MAX_TIMER_FETCH	Maximum wait time of all fetch operations that are timed.
+COUNT_INSERT	Number of all insert operations.
+SUM_TIMER_INSERT	Total wait time of all insert operations that are timed.
+MIN_TIMER_INSERT	Minimum wait time of all insert operations that are timed.
+AVG_TIMER_INSERT	Average wait time of all insert operations that are timed.
+MAX_TIMER_INSERT	Maximum wait time of all insert operations that are timed.
+COUNT_UPDATE	Number of all update operations.
+SUM_TIMER_UPDATE	Total wait time of all update operations that are timed.
+MIN_TIMER_UPDATE	Minimum wait time of all update operations that are timed.
+AVG_TIMER_UPDATE	Average wait time of all update operations that are timed.
+MAX_TIMER_UPDATE	Maximum wait time of all update operations that are timed.
+COUNT_DELETE	Number of all delete operations.
+SUM_TIMER_DELETE	Total wait time of all delete operations that are timed.
+MIN_TIMER_DELETE	Minimum wait time of all delete operations that are timed.
+AVG_TIMER_DELETE	Average wait time of all delete operations that are timed.
+MAX_TIMER_DELETE	Maximum wait time of all delete operations that are timed.

mysql-test/suite/perfschema/r/dml_tiws_by_table.result

@@ -24,3 +24,48 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.table_io_waits_summary_by_table WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'table_io_waits_summary_by_table'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='table_io_waits_summary_by_table';
+column_name	column_comment
+OBJECT_TYPE	Since this table records waits by table, always set to TABLE.
+OBJECT_SCHEMA	Schema name.
+OBJECT_NAME	Table name.
+COUNT_STAR	Number of summarized events and the sum of the x_READ and x_WRITE columns.
+SUM_TIMER_WAIT	Total wait time of the summarized events that are timed.
+MIN_TIMER_WAIT	Minimum wait time of the summarized events that are timed.
+AVG_TIMER_WAIT	Average wait time of the summarized events that are timed.
+MAX_TIMER_WAIT	Maximum wait time of the summarized events that are timed.
+COUNT_READ	Number of all read operations, and the sum of the equivalent x_FETCH columns.
+SUM_TIMER_READ	Total wait time of all read operations that are timed.
+MIN_TIMER_READ	Minimum wait time of all read operations that are timed.
+AVG_TIMER_READ	Average wait time of all read operations that are timed.
+MAX_TIMER_READ	Maximum wait time of all read operations that are timed.
+COUNT_WRITE	Number of all write operations, and the sum of the equivalent x_INSERT, x_UPDATE and x_DELETE columns.
+SUM_TIMER_WRITE	Total wait time of all write operations that are timed.
+MIN_TIMER_WRITE	Minimum wait time of all write operations that are timed.
+AVG_TIMER_WRITE	Average wait time of all write operations that are timed.
+MAX_TIMER_WRITE	Maximum wait time of all write operations that are timed.
+COUNT_FETCH	Number of all fetch operations.
+SUM_TIMER_FETCH	Total wait time of all fetch operations that are timed.
+MIN_TIMER_FETCH	Minimum wait time of all fetch operations that are timed.
+AVG_TIMER_FETCH	Average wait time of all fetch operations that are timed.
+MAX_TIMER_FETCH	Maximum wait time of all fetch operations that are timed.
+COUNT_INSERT	Number of all insert operations.
+SUM_TIMER_INSERT	Total wait time of all insert operations that are timed.
+MIN_TIMER_INSERT	Minimum wait time of all insert operations that are timed.
+AVG_TIMER_INSERT	Average wait time of all insert operations that are timed.
+MAX_TIMER_INSERT	Maximum wait time of all insert operations that are timed.
+COUNT_UPDATE	Number of all update operations.
+SUM_TIMER_UPDATE	Total wait time of all update operations that are timed.
+MIN_TIMER_UPDATE	Minimum wait time of all update operations that are timed.
+AVG_TIMER_UPDATE	Average wait time of all update operations that are timed.
+MAX_TIMER_UPDATE	Maximum wait time of all update operations that are timed.
+COUNT_DELETE	Number of all delete operations.
+SUM_TIMER_DELETE	Total wait time of all delete operations that are timed.
+MIN_TIMER_DELETE	Minimum wait time of all delete operations that are timed.
+AVG_TIMER_DELETE	Average wait time of all delete operations that are timed.
+MAX_TIMER_DELETE	Maximum wait time of all delete operations that are timed.

mysql-test/suite/perfschema/r/dml_tlws_by_table.result

@@ -24,3 +24,83 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.table_lock_waits_summary_by_table WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'table_lock_waits_summary_by_table'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='table_lock_waits_summary_by_table';
+column_name	column_comment
+OBJECT_TYPE	Since this table records waits by table, always set to TABLE.
+OBJECT_SCHEMA	Schema name.
+OBJECT_NAME	Table name.
+COUNT_STAR	Number of summarized events and the sum of the x_READ and x_WRITE columns.
+SUM_TIMER_WAIT	Total wait time of the summarized events that are timed.
+MIN_TIMER_WAIT	Minimum wait time of the summarized events that are timed.
+AVG_TIMER_WAIT	Average wait time of the summarized events that are timed.
+MAX_TIMER_WAIT	Maximum wait time of the summarized events that are timed.
+COUNT_READ	Number of all read operations, and the sum of the equivalent x_READ_NORMAL, x_READ_WITH_SHARED_LOCKS, x_READ_HIGH_PRIORITY and x_READ_NO_INSERT columns.
+SUM_TIMER_READ	Total wait time of all read operations that are timed.
+MIN_TIMER_READ	Minimum wait time of all read operations that are timed.
+AVG_TIMER_READ	Average wait time of all read operations that are timed.
+MAX_TIMER_READ	Maximum wait time of all read operations that are timed.
+COUNT_WRITE	Number of all write operations, and the sum of the equivalent x_WRITE_ALLOW_WRITE, x_WRITE_CONCURRENT_INSERT, x_WRITE_DELAYED, x_WRITE_LOW_PRIORITY and x_WRITE_NORMAL columns.
+SUM_TIMER_WRITE	Total wait time of all write operations that are timed.
+MIN_TIMER_WRITE	Minimum wait time of all write operations that are timed.
+AVG_TIMER_WRITE	Average wait time of all write operations that are timed.
+MAX_TIMER_WRITE	Maximum wait time of all write operations that are timed.
+COUNT_READ_NORMAL	Number of all internal read normal locks.
+SUM_TIMER_READ_NORMAL	Total wait time of all internal read normal locks that are timed.
+MIN_TIMER_READ_NORMAL	Minimum wait time of all internal read normal locks that are timed.
+AVG_TIMER_READ_NORMAL	Average wait time of all internal read normal locks that are timed.
+MAX_TIMER_READ_NORMAL	Maximum wait time of all internal read normal locks that are timed.
+COUNT_READ_WITH_SHARED_LOCKS	Number of all internal read with shared locks.
+SUM_TIMER_READ_WITH_SHARED_LOCKS	Total wait time of all internal read with shared locks that are timed.
+MIN_TIMER_READ_WITH_SHARED_LOCKS	Minimum wait time of all internal read with shared locks that are timed.
+AVG_TIMER_READ_WITH_SHARED_LOCKS	Average wait time of all internal read with shared locks that are timed.
+MAX_TIMER_READ_WITH_SHARED_LOCKS	Maximum wait time of all internal read with shared locks that are timed.
+COUNT_READ_HIGH_PRIORITY	Number of all internal read high priority locks.
+SUM_TIMER_READ_HIGH_PRIORITY	Total wait time of all internal read high priority locks that are timed.
+MIN_TIMER_READ_HIGH_PRIORITY	Minimum wait time of all internal read high priority locks that are timed.
+AVG_TIMER_READ_HIGH_PRIORITY	Average wait time of all internal read high priority locks that are timed.
+MAX_TIMER_READ_HIGH_PRIORITY	Maximum wait time of all internal read high priority locks that are timed.
+COUNT_READ_NO_INSERT	Number of all internal read no insert locks.
+SUM_TIMER_READ_NO_INSERT	Total wait time of all internal read no insert locks that are timed.
+MIN_TIMER_READ_NO_INSERT	Minimum wait time of all internal read no insert locks that are timed.
+AVG_TIMER_READ_NO_INSERT	Average wait time of all internal read no insert locks that are timed.
+MAX_TIMER_READ_NO_INSERT	Maximum wait time of all internal read no insert locks that are timed.
+COUNT_READ_EXTERNAL	Number of all external read locks.
+SUM_TIMER_READ_EXTERNAL	Total wait time of all external read locks that are timed.
+MIN_TIMER_READ_EXTERNAL	Minimum wait time of all external read locks that are timed.
+AVG_TIMER_READ_EXTERNAL	Average wait time of all external read locks that are timed.
+MAX_TIMER_READ_EXTERNAL	Maximum wait time of all external read locks that are timed.
+COUNT_WRITE_ALLOW_WRITE	Number of all internal read normal locks.
+SUM_TIMER_WRITE_ALLOW_WRITE	Total wait time of all internal write allow write locks that are timed.
+MIN_TIMER_WRITE_ALLOW_WRITE	Minimum wait time of all internal write allow write locks that are timed.
+AVG_TIMER_WRITE_ALLOW_WRITE	Average wait time of all internal write allow write locks that are timed.
+MAX_TIMER_WRITE_ALLOW_WRITE	Maximum wait time of all internal write allow write locks that are timed.
+COUNT_WRITE_CONCURRENT_INSERT	Number of all internal concurrent insert write locks.
+SUM_TIMER_WRITE_CONCURRENT_INSERT	Total wait time of all internal concurrent insert write locks that are timed.
+MIN_TIMER_WRITE_CONCURRENT_INSERT	Minimum wait time of all internal concurrent insert write locks that are timed.
+AVG_TIMER_WRITE_CONCURRENT_INSERT	Average wait time of all internal concurrent insert write locks that are timed.
+MAX_TIMER_WRITE_CONCURRENT_INSERT	Maximum wait time of all internal concurrent insert write locks that are timed.
+COUNT_WRITE_DELAYED	Number of all internal write delayed locks.
+SUM_TIMER_WRITE_DELAYED	Total wait time of all internal write delayed locks that are timed.
+MIN_TIMER_WRITE_DELAYED	Minimum wait time of all internal write delayed locks that are timed.
+AVG_TIMER_WRITE_DELAYED	Average wait time of all internal write delayed locks that are timed.
+MAX_TIMER_WRITE_DELAYED	Maximum wait time of all internal write delayed locks that are timed.
+COUNT_WRITE_LOW_PRIORITY	Number of all internal write low priority locks.
+SUM_TIMER_WRITE_LOW_PRIORITY	Total wait time of all internal write low priority locks that are timed.
+MIN_TIMER_WRITE_LOW_PRIORITY	Minimum wait time of all internal write low priority locks that are timed.
+AVG_TIMER_WRITE_LOW_PRIORITY	Average wait time of all internal write low priority locks that are timed.
+MAX_TIMER_WRITE_LOW_PRIORITY	Maximum wait time of all internal write low priority locks that are timed.
+COUNT_WRITE_NORMAL	Number of all internal write normal locks.
+SUM_TIMER_WRITE_NORMAL	Total wait time of all internal write normal locks that are timed.
+MIN_TIMER_WRITE_NORMAL	Minimum wait time of all internal write normal locks that are timed.
+AVG_TIMER_WRITE_NORMAL	Average wait time of all internal write normal locks that are timed.
+MAX_TIMER_WRITE_NORMAL	Maximum wait time of all internal write normal locks that are timed.
+COUNT_WRITE_EXTERNAL	Number of all external write locks.
+SUM_TIMER_WRITE_EXTERNAL	Total wait time of all external write locks that are timed.
+MIN_TIMER_WRITE_EXTERNAL	Minimum wait time of all external write locks that are timed.
+AVG_TIMER_WRITE_EXTERNAL	Average wait time of all external write locks that are timed.
+MAX_TIMER_WRITE_EXTERNAL	Maximum wait time of all external write locks that are timed.

mysql-test/suite/perfschema/r/dml_users.result

@@ -23,3 +23,13 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.users WRITE;
 ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'users'
 UNLOCK TABLES;
+#
+# MDEV-25325 column_comment for performance_schema tables
+#
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='users';
+column_name	column_comment
+USER	The connection's client user name for the connection, or NULL if an internal thread.
+CURRENT_CONNECTIONS	Current connections for the user.
+TOTAL_CONNECTIONS	Total connections for the user.

mysql-test/suite/perfschema/t/dml_accounts.test

@@ -39,3 +39,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.accounts WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='accounts';

mysql-test/suite/perfschema/t/dml_cond_instances.test

@@ -33,3 +33,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.cond_instances WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='cond_instances';

mysql-test/suite/perfschema/t/dml_esgs_by_account_by_event_name.test

@@ -40,3 +40,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_stages_summary_by_account_by_event_name WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_stages_summary_by_account_by_event_name';

mysql-test/suite/perfschema/t/dml_esgs_by_host_by_event_name.test

@@ -40,3 +40,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_stages_summary_by_host_by_event_name WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_stages_summary_by_host_by_event_name';

mysql-test/suite/perfschema/t/dml_esgs_by_thread_by_event_name.test

@@ -40,3 +40,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_stages_summary_by_thread_by_event_name WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_stages_summary_by_thread_by_event_name';

mysql-test/suite/perfschema/t/dml_esgs_by_user_by_event_name.test

@@ -40,3 +40,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_stages_summary_by_user_by_event_name WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_stages_summary_by_user_by_event_name';

mysql-test/suite/perfschema/t/dml_esgs_global_by_event_name.test

@@ -39,3 +39,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_stages_summary_global_by_event_name WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_stages_summary_global_by_event_name';

mysql-test/suite/perfschema/t/dml_esms_by_account_by_event_name.test

@@ -40,3 +40,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_statements_summary_by_account_by_event_name WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_statements_summary_by_account_by_event_name';

mysql-test/suite/perfschema/t/dml_esms_by_digest.test

@@ -61,3 +61,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_statements_summary_by_digest WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_statements_summary_by_digest';

mysql-test/suite/perfschema/t/dml_esms_by_host_by_event_name.test

@@ -40,3 +40,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_statements_summary_by_host_by_event_name WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_statements_summary_by_host_by_event_name';

mysql-test/suite/perfschema/t/dml_esms_by_thread_by_event_name.test

@@ -40,3 +40,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_statements_summary_by_thread_by_event_name WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_statements_summary_by_thread_by_event_name';

mysql-test/suite/perfschema/t/dml_esms_by_user_by_event_name.test

@@ -40,3 +40,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_statements_summary_by_user_by_event_name WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_statements_summary_by_user_by_event_name';

mysql-test/suite/perfschema/t/dml_esms_global_by_event_name.test

@@ -39,3 +39,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_statements_summary_global_by_event_name WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_statements_summary_global_by_event_name';

mysql-test/suite/perfschema/t/dml_events_stages_current.test

@@ -39,3 +39,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_stages_current WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_stages_current';

mysql-test/suite/perfschema/t/dml_events_stages_history.test

@@ -45,3 +45,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_stages_history WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_stages_history';

mysql-test/suite/perfschema/t/dml_events_stages_history_long.test

@@ -45,3 +45,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_stages_history_long WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_stages_history_long';

mysql-test/suite/perfschema/t/dml_events_statements_current.test

@@ -39,3 +39,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_statements_current WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_statements_current';

mysql-test/suite/perfschema/t/dml_events_statements_history.test

@@ -45,3 +45,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_statements_history WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_statements_history';

mysql-test/suite/perfschema/t/dml_events_statements_history_long.test

@@ -45,3 +45,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_statements_history_long WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_statements_history_long';

mysql-test/suite/perfschema/t/dml_events_waits_current.test

@@ -39,3 +39,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_waits_current WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_waits_current';

mysql-test/suite/perfschema/t/dml_events_waits_history.test

@@ -45,3 +45,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_waits_history WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_waits_history';

mysql-test/suite/perfschema/t/dml_events_waits_history_long.test

@@ -45,3 +45,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_waits_history_long WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_waits_history_long';

mysql-test/suite/perfschema/t/dml_ews_by_account_by_event_name.test

@@ -39,3 +39,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_waits_summary_by_account_by_event_name WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_waits_summary_by_account_by_event_name';

mysql-test/suite/perfschema/t/dml_ews_by_host_by_event_name.test

@@ -39,3 +39,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_waits_summary_by_host_by_event_name WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_waits_summary_by_host_by_event_name';

mysql-test/suite/perfschema/t/dml_ews_by_instance.test

@@ -52,3 +52,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_waits_summary_by_instance WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_waits_summary_by_instance';

mysql-test/suite/perfschema/t/dml_ews_by_thread_by_event_name.test

@@ -40,3 +40,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_waits_summary_by_thread_by_event_name WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_waits_summary_by_thread_by_event_name';

mysql-test/suite/perfschema/t/dml_ews_by_user_by_event_name.test

@@ -39,3 +39,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_waits_summary_by_user_by_event_name WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_waits_summary_by_user_by_event_name';

mysql-test/suite/perfschema/t/dml_ews_global_by_event_name.test

@@ -39,3 +39,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.events_waits_summary_global_by_event_name WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='events_waits_summary_global_by_event_name';

mysql-test/suite/perfschema/t/dml_file_instances.test

@@ -33,3 +33,11 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.file_instances WRITE;
 UNLOCK TABLES;
 
+
+
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='file_instances';

mysql-test/suite/perfschema/t/dml_fs_by_event_name.test

@@ -39,3 +39,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.file_summary_by_event_name WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='file_summary_by_event_name';

mysql-test/suite/perfschema/t/dml_fs_by_instance.test

@@ -39,3 +39,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.file_summary_by_instance WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='file_summary_by_instance';

mysql-test/suite/perfschema/t/dml_host_cache.test

@@ -41,3 +41,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.host_cache WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='host_cache';

mysql-test/suite/perfschema/t/dml_hosts.test

@@ -39,3 +39,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.hosts WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='hosts';

mysql-test/suite/perfschema/t/dml_mutex_instances.test

@@ -33,3 +33,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.mutex_instances WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='mutex_instances';

mysql-test/suite/perfschema/t/dml_os_global_by_type.test

@@ -55,3 +55,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.objects_summary_global_by_type WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='objects_summary_global_by_type';

mysql-test/suite/perfschema/t/dml_performance_timers.test

@@ -35,3 +35,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.performance_timers WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='performance_timers';

mysql-test/suite/perfschema/t/dml_rwlock_instances.test

@@ -33,3 +33,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.rwlock_instances WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='rwlock_instances';

mysql-test/suite/perfschema/t/dml_session_account_connect_attrs.test

+# Tests for PERFORMANCE_SCHEMA
+
 --source include/not_embedded.inc
 --source include/have_perfschema.inc
 
@@ -36,3 +38,10 @@ UNLOCK TABLES;
 -- error ER_TABLEACCESS_DENIED_ERROR
 LOCK TABLES performance_schema.session_account_connect_attrs WRITE;
 UNLOCK TABLES;
+
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='session_account_connect_attrs';

mysql-test/suite/perfschema/t/dml_session_connect_attrs.test

+# Tests for PERFORMANCE_SCHEMA
+
 --source include/not_embedded.inc
 --source include/have_perfschema.inc
 
@@ -36,3 +38,10 @@ UNLOCK TABLES;
 -- error ER_TABLEACCESS_DENIED_ERROR
 LOCK TABLES performance_schema.session_connect_attrs WRITE;
 UNLOCK TABLES;
+
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='session_connect_attrs';

mysql-test/suite/perfschema/t/dml_setup_actors.test

@@ -70,3 +70,9 @@ insert into performance_schema.setup_actors
   select * from test.setup_actors;
 drop table test.setup_actors;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='setup_actors';

mysql-test/suite/perfschema/t/dml_setup_consumers.test

@@ -38,3 +38,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.setup_consumers WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='setup_consumers';

mysql-test/suite/perfschema/t/dml_setup_instruments.test

@@ -98,3 +98,10 @@ ORDER BY RAND();
 update performance_schema.setup_instruments set timed='YES';
 --enable_query_log
 
+
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='setup_instruments';

mysql-test/suite/perfschema/t/dml_setup_objects.test

@@ -94,3 +94,9 @@ insert into performance_schema.setup_objects
   select * from test.setup_objects;
 drop table test.setup_objects;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='setup_objects';

mysql-test/suite/perfschema/t/dml_setup_timers.test

@@ -64,3 +64,9 @@ update performance_schema.setup_timers
 
 select * from performance_schema.setup_timers;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='setup_timers';

mysql-test/suite/perfschema/t/dml_socket_instances.test

@@ -33,3 +33,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.socket_instances WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='socket_instances';

mysql-test/suite/perfschema/t/dml_socket_summary_by_event_name.test

@@ -40,3 +40,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.socket_summary_by_event_name WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='socket_summary_by_event_name';

mysql-test/suite/perfschema/t/dml_socket_summary_by_instance.test

@@ -40,3 +40,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.socket_summary_by_instance WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='socket_summary_by_instance';

mysql-test/suite/perfschema/t/dml_threads.test

@@ -48,3 +48,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.threads WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='threads';

mysql-test/suite/perfschema/t/dml_tiws_by_index_usage.test

@@ -40,3 +40,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.table_io_waits_summary_by_index_usage WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='table_io_waits_summary_by_index_usage';

mysql-test/suite/perfschema/t/dml_tiws_by_table.test

@@ -40,3 +40,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.table_io_waits_summary_by_table WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='table_io_waits_summary_by_table';

mysql-test/suite/perfschema/t/dml_tlws_by_table.test

@@ -40,3 +40,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.table_lock_waits_summary_by_table WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='table_lock_waits_summary_by_table';

mysql-test/suite/perfschema/t/dml_users.test

@@ -39,3 +39,9 @@ UNLOCK TABLES;
 LOCK TABLES performance_schema.users WRITE;
 UNLOCK TABLES;
 
+--echo #
+--echo # MDEV-25325 column_comment for performance_schema tables
+--echo #
+select column_name, column_comment 
+from information_schema.columns 
+where table_schema='performance_schema' and table_name='users';

mysql-test/suite/perfschema/t/table_schema.test

@@ -55,3 +55,8 @@ select count(*) from information_schema.columns
 
 select (@count_object_columns - @count_object_unsigned) = 0;
 
+# Confirm that all columns have comments
+#
+select count(*) from information_schema.columns
+   where table_schema="performance_schema"
+   and (column_comment is null or column_comment = '');

storage/perfschema/table_accounts.cc

@@ -43,10 +43,10 @@ table_accounts::m_share=
   sizeof(PFS_simple_index), /* ref length */
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE accounts("
-                      "USER CHAR(" STRINGIFY_ARG(USERNAME_CHAR_LENGTH) ") collate utf8_bin default null,"
-                      "HOST CHAR(" STRINGIFY_ARG(HOSTNAME_LENGTH) ") collate utf8_bin default null,"
-                      "CURRENT_CONNECTIONS bigint not null,"
-                      "TOTAL_CONNECTIONS bigint not null)") }
+                      "USER CHAR(" STRINGIFY_ARG(USERNAME_CHAR_LENGTH) ") collate utf8_bin default null comment 'The connection''s client user name for the connection, or NULL if an internal thread.',"
+                      "HOST CHAR(" STRINGIFY_ARG(HOSTNAME_LENGTH) ") collate utf8_bin default null comment 'The connection client''s host name, or NULL if an internal thread.',"
+                      "CURRENT_CONNECTIONS bigint not null comment 'Current connections for the account.',"
+                      "TOTAL_CONNECTIONS bigint not null comment 'Total connections for the account.')") }
 };
 
 PFS_engine_table* table_accounts::create()

storage/perfschema/table_esgs_by_account_by_event_name.cc

@@ -49,14 +49,14 @@ table_esgs_by_account_by_event_name::m_share=
   sizeof(pos_esgs_by_account_by_event_name),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE events_stages_summary_by_account_by_event_name("
-                      "USER CHAR(" STRINGIFY_ARG(USERNAME_CHAR_LENGTH) ") collate utf8_bin default null,"
-                      "HOST CHAR(" STRINGIFY_ARG(HOSTNAME_LENGTH) ") collate utf8_bin default null,"
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "COUNT_STAR BIGINT unsigned not null,"
-                      "SUM_TIMER_WAIT BIGINT unsigned not null,"
-                      "MIN_TIMER_WAIT BIGINT unsigned not null,"
-                      "AVG_TIMER_WAIT BIGINT unsigned not null,"
-                      "MAX_TIMER_WAIT BIGINT unsigned not null)") }
+                      "USER CHAR(" STRINGIFY_ARG(USERNAME_CHAR_LENGTH) ") collate utf8_bin default null comment 'User. Used together with HOST and EVENT_NAME for grouping events.',"
+                      "HOST CHAR(" STRINGIFY_ARG(HOSTNAME_LENGTH) ") collate utf8_bin default null comment 'Host. Used together with USER and EVENT_NAME for grouping events.',"
+                      "EVENT_NAME VARCHAR(128) not null comment 'Event name. Used together with USER and HOST for grouping events.',"
+                      "COUNT_STAR BIGINT unsigned not null comment 'Number of summarized events, which includes all timed and untimed events.',"
+                      "SUM_TIMER_WAIT BIGINT unsigned not null comment 'Total wait time of the timed summarized events.',"
+                      "MIN_TIMER_WAIT BIGINT unsigned not null comment 'Minimum wait time of the timed summarized events.',"
+                      "AVG_TIMER_WAIT BIGINT unsigned not null comment 'Average wait time of the timed summarized events.',"
+                      "MAX_TIMER_WAIT BIGINT unsigned not null comment 'Maximum wait time of the timed summarized events.')") }
 };
 
 PFS_engine_table*

storage/perfschema/table_esgs_by_host_by_event_name.cc

@@ -50,13 +50,13 @@ table_esgs_by_host_by_event_name::m_share=
   sizeof(pos_esgs_by_host_by_event_name),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE events_stages_summary_by_host_by_event_name("
-                      "HOST CHAR(" STRINGIFY_ARG(HOSTNAME_LENGTH) ") collate utf8_bin default null,"
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "COUNT_STAR BIGINT unsigned not null,"
-                      "SUM_TIMER_WAIT BIGINT unsigned not null,"
-                      "MIN_TIMER_WAIT BIGINT unsigned not null,"
-                      "AVG_TIMER_WAIT BIGINT unsigned not null,"
-                      "MAX_TIMER_WAIT BIGINT unsigned not null)") }
+                      "HOST CHAR(" STRINGIFY_ARG(HOSTNAME_LENGTH) ") collate utf8_bin default null comment 'Host. Used together with EVENT_NAME for grouping events.',"
+                      "EVENT_NAME VARCHAR(128) not null comment 'Event name. Used together with HOST for grouping events.',"
+                      "COUNT_STAR BIGINT unsigned not null comment 'Number of summarized events, which includes all timed and untimed events.',"
+                      "SUM_TIMER_WAIT BIGINT unsigned not null comment 'Total wait time of the timed summarized events.',"
+                      "MIN_TIMER_WAIT BIGINT unsigned not null comment 'Minimum wait time of the timed summarized events.',"
+                      "AVG_TIMER_WAIT BIGINT unsigned not null comment 'Average wait time of the timed summarized events.',"
+                      "MAX_TIMER_WAIT BIGINT unsigned not null comment 'Maximum wait time of the timed summarized events.')") }
 };
 
 PFS_engine_table*

storage/perfschema/table_esgs_by_thread_by_event_name.cc

@@ -49,13 +49,13 @@ table_esgs_by_thread_by_event_name::m_share=
   sizeof(pos_esgs_by_thread_by_event_name),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE events_stages_summary_by_thread_by_event_name("
-                      "THREAD_ID BIGINT unsigned not null,"
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "COUNT_STAR BIGINT unsigned not null,"
-                      "SUM_TIMER_WAIT BIGINT unsigned not null,"
-                      "MIN_TIMER_WAIT BIGINT unsigned not null,"
-                      "AVG_TIMER_WAIT BIGINT unsigned not null,"
-                      "MAX_TIMER_WAIT BIGINT unsigned not null)") }
+                      "THREAD_ID BIGINT unsigned not null comment 'Thread associated with the event. Together with EVENT_NAME uniquely identifies the row.',"
+                      "EVENT_NAME VARCHAR(128) not null comment 'Event name. Used together with THREAD_ID for grouping events.',"
+                      "COUNT_STAR BIGINT unsigned not null comment 'Number of summarized events, which includes all timed and untimed events.',"
+                      "SUM_TIMER_WAIT BIGINT unsigned not null comment 'Total wait time of the timed summarized events.',"
+                      "MIN_TIMER_WAIT BIGINT unsigned not null comment 'Minimum wait time of the timed summarized events.',"
+                      "AVG_TIMER_WAIT BIGINT unsigned not null comment 'Average wait time of the timed summarized events.',"
+                      "MAX_TIMER_WAIT BIGINT unsigned not null comment 'Maximum wait time of the timed summarized events.')") }
 };
 
 PFS_engine_table*

storage/perfschema/table_esgs_by_user_by_event_name.cc

@@ -50,13 +50,13 @@ table_esgs_by_user_by_event_name::m_share=
   sizeof(pos_esgs_by_user_by_event_name),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE events_stages_summary_by_user_by_event_name("
-                      "USER CHAR(" STRINGIFY_ARG(USERNAME_CHAR_LENGTH) ") collate utf8_bin default null,"
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "COUNT_STAR BIGINT unsigned not null,"
-                      "SUM_TIMER_WAIT BIGINT unsigned not null,"
-                      "MIN_TIMER_WAIT BIGINT unsigned not null,"
-                      "AVG_TIMER_WAIT BIGINT unsigned not null,"
-                      "MAX_TIMER_WAIT BIGINT unsigned not null)") }
+                      "USER CHAR(" STRINGIFY_ARG(USERNAME_CHAR_LENGTH) ") collate utf8_bin default null comment 'User. Used together with EVENT_NAME for grouping events.',"
+                      "EVENT_NAME VARCHAR(128) not null comment 'Event name. Used together with USER for grouping events.',"
+                      "COUNT_STAR BIGINT unsigned not null comment 'Number of summarized events, which includes all timed and untimed events.',"
+                      "SUM_TIMER_WAIT BIGINT unsigned not null comment 'Total wait time of the timed summarized events.',"
+                      "MIN_TIMER_WAIT BIGINT unsigned not null comment 'Minimum wait time of the timed summarized events.',"
+                      "AVG_TIMER_WAIT BIGINT unsigned not null comment 'Average wait time of the timed summarized events.',"
+                      "MAX_TIMER_WAIT BIGINT unsigned not null comment 'Maximum wait time of the timed summarized events.')") }
 };
 
 PFS_engine_table*

storage/perfschema/table_esgs_global_by_event_name.cc

@@ -51,12 +51,12 @@ table_esgs_global_by_event_name::m_share=
   sizeof(PFS_simple_index),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE events_stages_summary_global_by_event_name("
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "COUNT_STAR BIGINT unsigned not null,"
-                      "SUM_TIMER_WAIT BIGINT unsigned not null,"
-                      "MIN_TIMER_WAIT BIGINT unsigned not null,"
-                      "AVG_TIMER_WAIT BIGINT unsigned not null,"
-                      "MAX_TIMER_WAIT BIGINT unsigned not null)") }
+                      "EVENT_NAME VARCHAR(128) not null comment 'Event name.',"
+                      "COUNT_STAR BIGINT unsigned not null comment 'Number of summarized events, which includes all timed and untimed events.',"
+                      "SUM_TIMER_WAIT BIGINT unsigned not null comment 'Total wait time of the timed summarized events.',"
+                      "MIN_TIMER_WAIT BIGINT unsigned not null comment 'Minimum wait time of the timed summarized events.',"
+                      "AVG_TIMER_WAIT BIGINT unsigned not null comment 'Average wait time of the timed summarized events.',"
+                      "MAX_TIMER_WAIT BIGINT unsigned not null comment 'Maximum wait time of the timed summarized events.')") }
 };
 
 PFS_engine_table*

storage/perfschema/table_esms_by_account_by_event_name.cc

@@ -49,33 +49,33 @@ table_esms_by_account_by_event_name::m_share=
   sizeof(pos_esms_by_account_by_event_name),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE events_statements_summary_by_account_by_event_name("
-                      "USER CHAR(" STRINGIFY_ARG(USERNAME_CHAR_LENGTH) ") collate utf8_bin default null,"
-                      "HOST CHAR(" STRINGIFY_ARG(HOSTNAME_LENGTH) ") collate utf8_bin default null,"
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "COUNT_STAR BIGINT unsigned not null,"
-                      "SUM_TIMER_WAIT BIGINT unsigned not null,"
-                      "MIN_TIMER_WAIT BIGINT unsigned not null,"
-                      "AVG_TIMER_WAIT BIGINT unsigned not null,"
-                      "MAX_TIMER_WAIT BIGINT unsigned not null,"
-                      "SUM_LOCK_TIME BIGINT unsigned not null,"
-                      "SUM_ERRORS BIGINT unsigned not null,"
-                      "SUM_WARNINGS BIGINT unsigned not null,"
-                      "SUM_ROWS_AFFECTED BIGINT unsigned not null,"
-                      "SUM_ROWS_SENT BIGINT unsigned not null,"
-                      "SUM_ROWS_EXAMINED BIGINT unsigned not null,"
-                      "SUM_CREATED_TMP_DISK_TABLES BIGINT unsigned not null,"
-                      "SUM_CREATED_TMP_TABLES BIGINT unsigned not null,"
-                      "SUM_SELECT_FULL_JOIN BIGINT unsigned not null,"
-                      "SUM_SELECT_FULL_RANGE_JOIN BIGINT unsigned not null,"
-                      "SUM_SELECT_RANGE BIGINT unsigned not null,"
-                      "SUM_SELECT_RANGE_CHECK BIGINT unsigned not null,"
-                      "SUM_SELECT_SCAN BIGINT unsigned not null,"
-                      "SUM_SORT_MERGE_PASSES BIGINT unsigned not null,"
-                      "SUM_SORT_RANGE BIGINT unsigned not null,"
-                      "SUM_SORT_ROWS BIGINT unsigned not null,"
-                      "SUM_SORT_SCAN BIGINT unsigned not null,"
-                      "SUM_NO_INDEX_USED BIGINT unsigned not null,"
-                      "SUM_NO_GOOD_INDEX_USED BIGINT unsigned not null)") }
+                      "USER CHAR(" STRINGIFY_ARG(USERNAME_CHAR_LENGTH) ") collate utf8_bin default null comment 'User. Used together with HOST and EVENT_NAME for grouping events.',"
+                      "HOST CHAR(" STRINGIFY_ARG(HOSTNAME_LENGTH) ") collate utf8_bin default null comment 'Host. Used together with USER and EVENT_NAME for grouping events.',"
+                      "EVENT_NAME VARCHAR(128) not null comment 'Event name. Used together with USER and HOST for grouping events.',"
+                      "COUNT_STAR BIGINT unsigned not null comment 'Number of summarized events',"
+                      "SUM_TIMER_WAIT BIGINT unsigned not null comment 'Total wait time of the summarized events that are timed.',"
+                      "MIN_TIMER_WAIT BIGINT unsigned not null comment 'Minimum wait time of the summarized events that are timed.',"
+                      "AVG_TIMER_WAIT BIGINT unsigned not null comment 'Average wait time of the summarized events that are timed.',"
+                      "MAX_TIMER_WAIT BIGINT unsigned not null comment 'Maximum wait time of the summarized events that are timed.',"
+                      "SUM_LOCK_TIME BIGINT unsigned not null comment 'Sum of the LOCK_TIME column in the events_statements_current table.',"
+                      "SUM_ERRORS BIGINT unsigned not null comment 'Sum of the ERRORS column in the events_statements_current table.',"
+                      "SUM_WARNINGS BIGINT unsigned not null comment 'Sum of the WARNINGS column in the events_statements_current table.',"
+                      "SUM_ROWS_AFFECTED BIGINT unsigned not null comment 'Sum of the ROWS_AFFECTED column in the events_statements_current table.',"
+                      "SUM_ROWS_SENT BIGINT unsigned not null comment 'Sum of the ROWS_SENT column in the events_statements_current table.',"
+                      "SUM_ROWS_EXAMINED BIGINT unsigned not null comment 'Sum of the ROWS_EXAMINED column in the events_statements_current table.',"
+                      "SUM_CREATED_TMP_DISK_TABLES BIGINT unsigned not null comment 'Sum of the CREATED_TMP_DISK_TABLES column in the events_statements_current table.',"
+                      "SUM_CREATED_TMP_TABLES BIGINT unsigned not null comment 'Sum of the CREATED_TMP_TABLES column in the events_statements_current table.',"
+                      "SUM_SELECT_FULL_JOIN BIGINT unsigned not null comment 'Sum of the SELECT_FULL_JOIN column in the events_statements_current table.',"
+                      "SUM_SELECT_FULL_RANGE_JOIN BIGINT unsigned not null comment 'Sum of the SELECT_FULL_RANGE_JOIN column in the events_statements_current table.',"
+                      "SUM_SELECT_RANGE BIGINT unsigned not null comment 'Sum of the SELECT_RANGE column in the events_statements_current table.',"
+                      "SUM_SELECT_RANGE_CHECK BIGINT unsigned not null comment 'Sum of the SELECT_RANGE_CHECK column in the events_statements_current table.',"
+                      "SUM_SELECT_SCAN BIGINT unsigned not null comment 'Sum of the SELECT_SCAN column in the events_statements_current table.',"
+                      "SUM_SORT_MERGE_PASSES BIGINT unsigned not null comment 'Sum of the SORT_MERGE_PASSES column in the events_statements_current table.',"
+                      "SUM_SORT_RANGE BIGINT unsigned not null comment 'Sum of the SORT_RANGE column in the events_statements_current table.',"
+                      "SUM_SORT_ROWS BIGINT unsigned not null comment 'Sum of the SORT_ROWS column in the events_statements_current table.',"
+                      "SUM_SORT_SCAN BIGINT unsigned not null comment 'Sum of the SORT_SCAN column in the events_statements_current table.',"
+                      "SUM_NO_INDEX_USED BIGINT unsigned not null comment 'Sum of the NO_INDEX_USED column in the events_statements_current table.',"
+                      "SUM_NO_GOOD_INDEX_USED BIGINT unsigned not null comment 'Sum of the NO_GOOD_INDEX_USED column in the events_statements_current table.')") }
 };
 
 PFS_engine_table*

storage/perfschema/table_esms_by_digest.cc

@@ -53,35 +53,35 @@ table_esms_by_digest::m_share=
   sizeof(PFS_simple_index),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE events_statements_summary_by_digest("
-                      "SCHEMA_NAME VARCHAR(64),"
-                      "DIGEST VARCHAR(32),"
-                      "DIGEST_TEXT LONGTEXT,"
-                      "COUNT_STAR BIGINT unsigned not null,"
-                      "SUM_TIMER_WAIT BIGINT unsigned not null,"
-                      "MIN_TIMER_WAIT BIGINT unsigned not null,"
-                      "AVG_TIMER_WAIT BIGINT unsigned not null,"
-                      "MAX_TIMER_WAIT BIGINT unsigned not null,"
-                      "SUM_LOCK_TIME BIGINT unsigned not null,"
-                      "SUM_ERRORS BIGINT unsigned not null,"
-                      "SUM_WARNINGS BIGINT unsigned not null,"
-                      "SUM_ROWS_AFFECTED BIGINT unsigned not null,"
-                      "SUM_ROWS_SENT BIGINT unsigned not null,"
-                      "SUM_ROWS_EXAMINED BIGINT unsigned not null,"
-                      "SUM_CREATED_TMP_DISK_TABLES BIGINT unsigned not null,"
-                      "SUM_CREATED_TMP_TABLES BIGINT unsigned not null,"
-                      "SUM_SELECT_FULL_JOIN BIGINT unsigned not null,"
-                      "SUM_SELECT_FULL_RANGE_JOIN BIGINT unsigned not null,"
-                      "SUM_SELECT_RANGE BIGINT unsigned not null,"
-                      "SUM_SELECT_RANGE_CHECK BIGINT unsigned not null,"
-                      "SUM_SELECT_SCAN BIGINT unsigned not null,"
-                      "SUM_SORT_MERGE_PASSES BIGINT unsigned not null,"
-                      "SUM_SORT_RANGE BIGINT unsigned not null,"
-                      "SUM_SORT_ROWS BIGINT unsigned not null,"
-                      "SUM_SORT_SCAN BIGINT unsigned not null,"
-                      "SUM_NO_INDEX_USED BIGINT unsigned not null,"
-                      "SUM_NO_GOOD_INDEX_USED BIGINT unsigned not null,"
-                      "FIRST_SEEN TIMESTAMP(0) NOT NULL default 0,"
-                      "LAST_SEEN TIMESTAMP(0) NOT NULL default 0)") }
+                      "SCHEMA_NAME VARCHAR(64) comment 'Database name. Records are summarised together with DIGEST.',"
+                      "DIGEST VARCHAR(32) comment 'Performance Schema digest. Records are summarised together with SCHEMA NAME.',"
+                      "DIGEST_TEXT LONGTEXT comment 'The unhashed form of the digest.',"
+                      "COUNT_STAR BIGINT unsigned not null comment 'Number of summarized events',"
+                      "SUM_TIMER_WAIT BIGINT unsigned not null comment 'Total wait time of the summarized events that are timed.',"
+                      "MIN_TIMER_WAIT BIGINT unsigned not null comment 'Minimum wait time of the summarized events that are timed.',"
+                      "AVG_TIMER_WAIT BIGINT unsigned not null comment 'Average wait time of the summarized events that are timed.',"
+                      "MAX_TIMER_WAIT BIGINT unsigned not null comment 'Maximum wait time of the summarized events that are timed.',"
+                      "SUM_LOCK_TIME BIGINT unsigned not null comment 'Sum of the LOCK_TIME column in the events_statements_current table.',"
+                      "SUM_ERRORS BIGINT unsigned not null comment 'Sum of the ERRORS column in the events_statements_current table.',"
+                      "SUM_WARNINGS BIGINT unsigned not null comment 'Sum of the WARNINGS column in the events_statements_current table.',"
+                      "SUM_ROWS_AFFECTED BIGINT unsigned not null comment 'Sum of the ROWS_AFFECTED column in the events_statements_current table.',"
+                      "SUM_ROWS_SENT BIGINT unsigned not null comment 'Sum of the ROWS_SENT column in the events_statements_current table.',"
+                      "SUM_ROWS_EXAMINED BIGINT unsigned not null comment 'Sum of the ROWS_EXAMINED column in the events_statements_current table.',"
+                      "SUM_CREATED_TMP_DISK_TABLES BIGINT unsigned not null comment 'Sum of the CREATED_TMP_DISK_TABLES column in the events_statements_current table.',"
+                      "SUM_CREATED_TMP_TABLES BIGINT unsigned not null comment 'Sum of the CREATED_TMP_TABLES column in the events_statements_current table.',"
+                      "SUM_SELECT_FULL_JOIN BIGINT unsigned not null comment 'Sum of the SELECT_FULL_JOIN column in the events_statements_current table.',"
+                      "SUM_SELECT_FULL_RANGE_JOIN BIGINT unsigned not null comment 'Sum of the SELECT_FULL_RANGE_JOIN column in the events_statements_current table.',"
+                      "SUM_SELECT_RANGE BIGINT unsigned not null comment 'Sum of the SELECT_RANGE column in the events_statements_current table.',"
+                      "SUM_SELECT_RANGE_CHECK BIGINT unsigned not null comment 'Sum of the SELECT_RANGE_CHECK column in the events_statements_current table.',"
+                      "SUM_SELECT_SCAN BIGINT unsigned not null comment 'Sum of the SELECT_SCAN column in the events_statements_current table.',"
+                      "SUM_SORT_MERGE_PASSES BIGINT unsigned not null comment 'Sum of the SORT_MERGE_PASSES column in the events_statements_current table.',"
+                      "SUM_SORT_RANGE BIGINT unsigned not null comment 'Sum of the SORT_RANGE column in the events_statements_current table.',"
+                      "SUM_SORT_ROWS BIGINT unsigned not null comment 'Sum of the SORT_ROWS column in the events_statements_current table.',"
+                      "SUM_SORT_SCAN BIGINT unsigned not null comment 'Sum of the SORT_SCAN column in the events_statements_current table.',"
+                      "SUM_NO_INDEX_USED BIGINT unsigned not null comment 'Sum of the NO_INDEX_USED column in the events_statements_current table.',"
+                      "SUM_NO_GOOD_INDEX_USED BIGINT unsigned not null comment 'Sum of the NO_GOOD_INDEX_USED column in the events_statements_current table.',"
+                      "FIRST_SEEN TIMESTAMP(0) NOT NULL default 0 comment 'Time at which the digest was first seen.',"
+                      "LAST_SEEN TIMESTAMP(0) NOT NULL default 0 comment 'Time at which the digest was most recently seen.')") }
 };
 
 PFS_engine_table*

storage/perfschema/table_esms_by_host_by_event_name.cc

@@ -50,32 +50,32 @@ table_esms_by_host_by_event_name::m_share=
   sizeof(pos_esms_by_host_by_event_name),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE events_statements_summary_by_host_by_event_name("
-                      "HOST CHAR(" STRINGIFY_ARG(HOSTNAME_LENGTH) ") collate utf8_bin default null,"
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "COUNT_STAR BIGINT unsigned not null,"
-                      "SUM_TIMER_WAIT BIGINT unsigned not null,"
-                      "MIN_TIMER_WAIT BIGINT unsigned not null,"
-                      "AVG_TIMER_WAIT BIGINT unsigned not null,"
-                      "MAX_TIMER_WAIT BIGINT unsigned not null,"
-                      "SUM_LOCK_TIME BIGINT unsigned not null,"
-                      "SUM_ERRORS BIGINT unsigned not null,"
-                      "SUM_WARNINGS BIGINT unsigned not null,"
-                      "SUM_ROWS_AFFECTED BIGINT unsigned not null,"
-                      "SUM_ROWS_SENT BIGINT unsigned not null,"
-                      "SUM_ROWS_EXAMINED BIGINT unsigned not null,"
-                      "SUM_CREATED_TMP_DISK_TABLES BIGINT unsigned not null,"
-                      "SUM_CREATED_TMP_TABLES BIGINT unsigned not null,"
-                      "SUM_SELECT_FULL_JOIN BIGINT unsigned not null,"
-                      "SUM_SELECT_FULL_RANGE_JOIN BIGINT unsigned not null,"
-                      "SUM_SELECT_RANGE BIGINT unsigned not null,"
-                      "SUM_SELECT_RANGE_CHECK BIGINT unsigned not null,"
-                      "SUM_SELECT_SCAN BIGINT unsigned not null,"
-                      "SUM_SORT_MERGE_PASSES BIGINT unsigned not null,"
-                      "SUM_SORT_RANGE BIGINT unsigned not null,"
-                      "SUM_SORT_ROWS BIGINT unsigned not null,"
-                      "SUM_SORT_SCAN BIGINT unsigned not null,"
-                      "SUM_NO_INDEX_USED BIGINT unsigned not null,"
-                      "SUM_NO_GOOD_INDEX_USED BIGINT unsigned not null)") }
+                      "HOST CHAR(" STRINGIFY_ARG(HOSTNAME_LENGTH) ") collate utf8_bin default null comment 'Host. Used together with EVENT_NAME for grouping events.',"
+                      "EVENT_NAME VARCHAR(128) not null comment 'Event name. Used together with HOST for grouping events.',"
+                      "COUNT_STAR BIGINT unsigned not null comment 'Number of summarized events',"
+                      "SUM_TIMER_WAIT BIGINT unsigned not null comment 'Total wait time of the summarized events that are timed.',"
+                      "MIN_TIMER_WAIT BIGINT unsigned not null comment 'Minimum wait time of the summarized events that are timed.',"
+                      "AVG_TIMER_WAIT BIGINT unsigned not null comment 'Average wait time of the summarized events that are timed.',"
+                      "MAX_TIMER_WAIT BIGINT unsigned not null comment 'Maximum wait time of the summarized events that are timed.',"
+                      "SUM_LOCK_TIME BIGINT unsigned not null comment 'Sum of the LOCK_TIME column in the events_statements_currentd table.',"
+                      "SUM_ERRORS BIGINT unsigned not null comment 'Sum of the ERRORS column in the events_statements_current table.',"
+                      "SUM_WARNINGS BIGINT unsigned not null comment 'Sum of the WARNINGS column in the events_statements_current table.',"
+                      "SUM_ROWS_AFFECTED BIGINT unsigned not null comment 'Sum of the ROWS_AFFECTED column in the events_statements_current table.',"
+                      "SUM_ROWS_SENT BIGINT unsigned not null comment 'Sum of the ROWS_SENT column in the events_statements_current table.',"
+                      "SUM_ROWS_EXAMINED BIGINT unsigned not null comment 'Sum of the ROWS_EXAMINED column in the events_statements_current table.',"
+                      "SUM_CREATED_TMP_DISK_TABLES BIGINT unsigned not null comment 'Sum of the CREATED_TMP_DISK_TABLES column in the events_statements_current table.',"
+                      "SUM_CREATED_TMP_TABLES BIGINT unsigned not null comment 'Sum of the CREATED_TMP_TABLES column in the events_statements_current table.',"
+                      "SUM_SELECT_FULL_JOIN BIGINT unsigned not null comment 'Sum of the SELECT_FULL_JOIN column in the events_statements_current table.',"
+                      "SUM_SELECT_FULL_RANGE_JOIN BIGINT unsigned not null comment 'Sum of the SELECT_FULL_RANGE_JOINW column in the events_statements_current table.',"
+                      "SUM_SELECT_RANGE BIGINT unsigned not null comment 'Sum of the SELECT_RANGE column in the events_statements_current table.',"
+                      "SUM_SELECT_RANGE_CHECK BIGINT unsigned not null comment 'Sum of the SELECT_RANGE_CHECK column in the events_statements_current table.',"
+                      "SUM_SELECT_SCAN BIGINT unsigned not null comment 'Sum of the SELECT_SCAN column in the events_statements_current table.',"
+                      "SUM_SORT_MERGE_PASSES BIGINT unsigned not null comment 'Sum of the SORT_MERGE_PASSES column in the events_statements_current table.',"
+                      "SUM_SORT_RANGE BIGINT unsigned not null comment 'Sum of the SORT_RANGE column in the events_statements_current table.',"
+                      "SUM_SORT_ROWS BIGINT unsigned not null comment 'Sum of the SORT_ROWS column in the events_statements_current table.',"
+                      "SUM_SORT_SCAN BIGINT unsigned not null comment 'Sum of the SORT_SCAN column in the events_statements_current table.',"
+                      "SUM_NO_INDEX_USED BIGINT unsigned not null comment 'Sum of the NO_INDEX_USED column in the events_statements_current table.',"
+                      "SUM_NO_GOOD_INDEX_USED BIGINT unsigned not null comment 'Sum of the NO_GOOD_INDEX_USED column in the events_statements_current table.')") }
 };
 
 PFS_engine_table*

storage/perfschema/table_esms_by_thread_by_event_name.cc

@@ -49,32 +49,32 @@ table_esms_by_thread_by_event_name::m_share=
   sizeof(pos_esms_by_thread_by_event_name),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE events_statements_summary_by_thread_by_event_name("
-                      "THREAD_ID BIGINT unsigned not null,"
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "COUNT_STAR BIGINT unsigned not null,"
-                      "SUM_TIMER_WAIT BIGINT unsigned not null,"
-                      "MIN_TIMER_WAIT BIGINT unsigned not null,"
-                      "AVG_TIMER_WAIT BIGINT unsigned not null,"
-                      "MAX_TIMER_WAIT BIGINT unsigned not null,"
-                      "SUM_LOCK_TIME BIGINT unsigned not null,"
-                      "SUM_ERRORS BIGINT unsigned not null,"
-                      "SUM_WARNINGS BIGINT unsigned not null,"
-                      "SUM_ROWS_AFFECTED BIGINT unsigned not null,"
-                      "SUM_ROWS_SENT BIGINT unsigned not null,"
-                      "SUM_ROWS_EXAMINED BIGINT unsigned not null,"
-                      "SUM_CREATED_TMP_DISK_TABLES BIGINT unsigned not null,"
-                      "SUM_CREATED_TMP_TABLES BIGINT unsigned not null,"
-                      "SUM_SELECT_FULL_JOIN BIGINT unsigned not null,"
-                      "SUM_SELECT_FULL_RANGE_JOIN BIGINT unsigned not null,"
-                      "SUM_SELECT_RANGE BIGINT unsigned not null,"
-                      "SUM_SELECT_RANGE_CHECK BIGINT unsigned not null,"
-                      "SUM_SELECT_SCAN BIGINT unsigned not null,"
-                      "SUM_SORT_MERGE_PASSES BIGINT unsigned not null,"
-                      "SUM_SORT_RANGE BIGINT unsigned not null,"
-                      "SUM_SORT_ROWS BIGINT unsigned not null,"
-                      "SUM_SORT_SCAN BIGINT unsigned not null,"
-                      "SUM_NO_INDEX_USED BIGINT unsigned not null,"
-                      "SUM_NO_GOOD_INDEX_USED BIGINT unsigned not null)") }
+                      "THREAD_ID BIGINT unsigned not null comment 'Thread associated with the event. Together with EVENT_NAME uniquely identifies the row.',"
+                      "EVENT_NAME VARCHAR(128) not null comment 'Event name. Used together with THREAD_ID for grouping events.',"
+                      "COUNT_STAR BIGINT unsigned not null comment 'Number of summarized events',"
+                      "SUM_TIMER_WAIT BIGINT unsigned not null comment 'Total wait time of the summarized events that are timed.',"
+                      "MIN_TIMER_WAIT BIGINT unsigned not null comment 'Minimum wait time of the summarized events that are timed.',"
+                      "AVG_TIMER_WAIT BIGINT unsigned not null comment 'Average wait time of the summarized events that are timed.',"
+                      "MAX_TIMER_WAIT BIGINT unsigned not null comment 'Maximum wait time of the summarized events that are timed.',"
+                      "SUM_LOCK_TIME BIGINT unsigned not null comment 'Sum of the LOCK_TIME column in the events_statements_current table.',"
+                      "SUM_ERRORS BIGINT unsigned not null comment 'Sum of the ERRORS column in the events_statements_current table.',"
+                      "SUM_WARNINGS BIGINT unsigned not null comment 'Sum of the WARNINGS column in the events_statements_current table.',"
+                      "SUM_ROWS_AFFECTED BIGINT unsigned not null comment 'Sum of the ROWS_AFFECTED column in the events_statements_current table.',"
+                      "SUM_ROWS_SENT BIGINT unsigned not null comment 'Sum of the ROWS_SENT column in the events_statements_current table.',"
+                      "SUM_ROWS_EXAMINED BIGINT unsigned not null comment 'Sum of the ROWS_EXAMINED column in the events_statements_current table.',"
+                      "SUM_CREATED_TMP_DISK_TABLES BIGINT unsigned not null comment 'Sum of the CREATED_TMP_DISK_TABLES column in the events_statements_current table.',"
+                      "SUM_CREATED_TMP_TABLES BIGINT unsigned not null comment 'Sum of the CREATED_TMP_TABLES column in the events_statements_current table.',"
+                      "SUM_SELECT_FULL_JOIN BIGINT unsigned not null comment 'Sum of the SELECT_FULL_JOIN column in the events_statements_current table.',"
+                      "SUM_SELECT_FULL_RANGE_JOIN BIGINT unsigned not null comment 'Sum of the SELECT_FULL_RANGE_JOIN column in the events_statements_current table.',"
+                      "SUM_SELECT_RANGE BIGINT unsigned not null comment 'Sum of the SELECT_RANGE column in the events_statements_current table.',"
+                      "SUM_SELECT_RANGE_CHECK BIGINT unsigned not null comment 'Sum of the SELECT_RANGE_CHECK column in the events_statements_current table.',"
+                      "SUM_SELECT_SCAN BIGINT unsigned not null comment 'Sum of the SELECT_SCAN column in the events_statements_current table.',"
+                      "SUM_SORT_MERGE_PASSES BIGINT unsigned not null comment 'Sum of the SORT_MERGE_PASSES column in the events_statements_current table.',"
+                      "SUM_SORT_RANGE BIGINT unsigned not null comment 'Sum of the SORT_RANGE column in the events_statements_current table.',"
+                      "SUM_SORT_ROWS BIGINT unsigned not null comment 'Sum of the SORT_ROWS column in the events_statements_current table.',"
+                      "SUM_SORT_SCAN BIGINT unsigned not null comment 'Sum of the SORT_SCAN column in the events_statements_current table.',"
+                      "SUM_NO_INDEX_USED BIGINT unsigned not null comment 'Sum of the NO_INDEX_USED column in the events_statements_current table.',"
+                      "SUM_NO_GOOD_INDEX_USED BIGINT unsigned not null comment 'Sum of the NO_GOOD_INDEX_USED column in the events_statements_current table.')") }
 };
 
 PFS_engine_table*

storage/perfschema/table_esms_by_user_by_event_name.cc

@@ -50,32 +50,32 @@ table_esms_by_user_by_event_name::m_share=
   sizeof(pos_esms_by_user_by_event_name),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE events_statements_summary_by_user_by_event_name("
-                      "USER CHAR(" STRINGIFY_ARG(USERNAME_CHAR_LENGTH) ") collate utf8_bin default null,"
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "COUNT_STAR BIGINT unsigned not null,"
-                      "SUM_TIMER_WAIT BIGINT unsigned not null,"
-                      "MIN_TIMER_WAIT BIGINT unsigned not null,"
-                      "AVG_TIMER_WAIT BIGINT unsigned not null,"
-                      "MAX_TIMER_WAIT BIGINT unsigned not null,"
-                      "SUM_LOCK_TIME BIGINT unsigned not null,"
-                      "SUM_ERRORS BIGINT unsigned not null,"
-                      "SUM_WARNINGS BIGINT unsigned not null,"
-                      "SUM_ROWS_AFFECTED BIGINT unsigned not null,"
-                      "SUM_ROWS_SENT BIGINT unsigned not null,"
-                      "SUM_ROWS_EXAMINED BIGINT unsigned not null,"
-                      "SUM_CREATED_TMP_DISK_TABLES BIGINT unsigned not null,"
-                      "SUM_CREATED_TMP_TABLES BIGINT unsigned not null,"
-                      "SUM_SELECT_FULL_JOIN BIGINT unsigned not null,"
-                      "SUM_SELECT_FULL_RANGE_JOIN BIGINT unsigned not null,"
-                      "SUM_SELECT_RANGE BIGINT unsigned not null,"
-                      "SUM_SELECT_RANGE_CHECK BIGINT unsigned not null,"
-                      "SUM_SELECT_SCAN BIGINT unsigned not null,"
-                      "SUM_SORT_MERGE_PASSES BIGINT unsigned not null,"
-                      "SUM_SORT_RANGE BIGINT unsigned not null,"
-                      "SUM_SORT_ROWS BIGINT unsigned not null,"
-                      "SUM_SORT_SCAN BIGINT unsigned not null,"
-                      "SUM_NO_INDEX_USED BIGINT unsigned not null,"
-                      "SUM_NO_GOOD_INDEX_USED BIGINT unsigned not null)") }
+                      "USER CHAR(" STRINGIFY_ARG(USERNAME_CHAR_LENGTH) ") collate utf8_bin default null comment 'User. Used together with EVENT_NAME for grouping events.',"
+                      "EVENT_NAME VARCHAR(128) not null comment 'Event name. Used together with USER for grouping events.',"
+                      "COUNT_STAR BIGINT unsigned not null comment 'Number of summarized events',"
+                      "SUM_TIMER_WAIT BIGINT unsigned not null comment 'Total wait time of the summarized events that are timed.',"
+                      "MIN_TIMER_WAIT BIGINT unsigned not null comment 'Minimum wait time of the summarized events that are timed.',"
+                      "AVG_TIMER_WAIT BIGINT unsigned not null comment 'Average wait time of the summarized events that are timed.',"
+                      "MAX_TIMER_WAIT BIGINT unsigned not null comment 'Maximum wait time of the summarized events that are timed.',"
+                      "SUM_LOCK_TIME BIGINT unsigned not null comment 'Sum of the LOCK_TIME column in the events_statements_current table.',"
+                      "SUM_ERRORS BIGINT unsigned not null comment 'Sum of the ERRORS column in the events_statements_current table.',"
+                      "SUM_WARNINGS BIGINT unsigned not null comment 'Sum of the WARNINGS column in the events_statements_current table.',"
+                      "SUM_ROWS_AFFECTED BIGINT unsigned not null comment 'Sum of the ROWS_AFFECTED column in the events_statements_current table.',"
+                      "SUM_ROWS_SENT BIGINT unsigned not null comment 'Sum of the ROWS_SENT column in the events_statements_current table.',"
+                      "SUM_ROWS_EXAMINED BIGINT unsigned not null comment 'Sum of the ROWS_EXAMINED column in the events_statements_current table.',"
+                      "SUM_CREATED_TMP_DISK_TABLES BIGINT unsigned not null comment 'Sum of the CREATED_TMP_DISK_TABLES column in the events_statements_current table.',"
+                      "SUM_CREATED_TMP_TABLES BIGINT unsigned not null comment 'Sum of the CREATED_TMP_TABLES column in the events_statements_current table.',"
+                      "SUM_SELECT_FULL_JOIN BIGINT unsigned not null comment 'Sum of the SELECT_FULL_JOIN column in the events_statements_current table.',"
+                      "SUM_SELECT_FULL_RANGE_JOIN BIGINT unsigned not null comment 'Sum of the SELECT_FULL_RANGE_JOIN column in the events_statements_current table.',"
+                      "SUM_SELECT_RANGE BIGINT unsigned not null comment 'Sum of the SELECT_RANGE column in the events_statements_current table.',"
+                      "SUM_SELECT_RANGE_CHECK BIGINT unsigned not null comment 'Sum of the SELECT_RANGE_CHECK column in the events_statements_current table.',"
+                      "SUM_SELECT_SCAN BIGINT unsigned not null comment 'Sum of the SELECT_SCAN column in the events_statements_current table.',"
+                      "SUM_SORT_MERGE_PASSES BIGINT unsigned not null comment 'Sum of the SORT_MERGE_PASSES column in the events_statements_current table.',"
+                      "SUM_SORT_RANGE BIGINT unsigned not null comment 'Sum of the SORT_RANGE column in the events_statements_current table.',"
+                      "SUM_SORT_ROWS BIGINT unsigned not null comment 'Sum of the SORT_ROWS column in the events_statements_current table.',"
+                      "SUM_SORT_SCAN BIGINT unsigned not null comment 'Sum of the SORT_SCAN column in the events_statements_current table.',"
+                      "SUM_NO_INDEX_USED BIGINT unsigned not null comment 'Sum of the NO_INDEX_USED column in the events_statements_current table.',"
+                      "SUM_NO_GOOD_INDEX_USED BIGINT unsigned not null comment 'Sum of the NO_GOOD_INDEX_USED column in the events_statements_current table.')") }
 };
 
 PFS_engine_table*

storage/perfschema/table_esms_global_by_event_name.cc

@@ -51,31 +51,31 @@ table_esms_global_by_event_name::m_share=
   sizeof(PFS_simple_index),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE events_statements_summary_global_by_event_name("
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "COUNT_STAR BIGINT unsigned not null,"
-                      "SUM_TIMER_WAIT BIGINT unsigned not null,"
-                      "MIN_TIMER_WAIT BIGINT unsigned not null,"
-                      "AVG_TIMER_WAIT BIGINT unsigned not null,"
-                      "MAX_TIMER_WAIT BIGINT unsigned not null,"
-                      "SUM_LOCK_TIME BIGINT unsigned not null,"
-                      "SUM_ERRORS BIGINT unsigned not null,"
-                      "SUM_WARNINGS BIGINT unsigned not null,"
-                      "SUM_ROWS_AFFECTED BIGINT unsigned not null,"
-                      "SUM_ROWS_SENT BIGINT unsigned not null,"
-                      "SUM_ROWS_EXAMINED BIGINT unsigned not null,"
-                      "SUM_CREATED_TMP_DISK_TABLES BIGINT unsigned not null,"
-                      "SUM_CREATED_TMP_TABLES BIGINT unsigned not null,"
-                      "SUM_SELECT_FULL_JOIN BIGINT unsigned not null,"
-                      "SUM_SELECT_FULL_RANGE_JOIN BIGINT unsigned not null,"
-                      "SUM_SELECT_RANGE BIGINT unsigned not null,"
-                      "SUM_SELECT_RANGE_CHECK BIGINT unsigned not null,"
-                      "SUM_SELECT_SCAN BIGINT unsigned not null,"
-                      "SUM_SORT_MERGE_PASSES BIGINT unsigned not null,"
-                      "SUM_SORT_RANGE BIGINT unsigned not null,"
-                      "SUM_SORT_ROWS BIGINT unsigned not null,"
-                      "SUM_SORT_SCAN BIGINT unsigned not null,"
-                      "SUM_NO_INDEX_USED BIGINT unsigned not null,"
-                      "SUM_NO_GOOD_INDEX_USED BIGINT unsigned not null)") }
+                      "EVENT_NAME VARCHAR(128) not null comment 'Event name.',"
+                      "COUNT_STAR BIGINT unsigned not null comment 'Number of summarized events',"
+                      "SUM_TIMER_WAIT BIGINT unsigned not null comment 'Total wait time of the summarized events that are timed.',"
+                      "MIN_TIMER_WAIT BIGINT unsigned not null comment 'Minimum wait time of the summarized events that are timed.',"
+                      "AVG_TIMER_WAIT BIGINT unsigned not null comment 'Average wait time of the summarized events that are timed.',"
+                      "MAX_TIMER_WAIT BIGINT unsigned not null comment 'Maximum wait time of the summarized events that are timed.',"
+                      "SUM_LOCK_TIME BIGINT unsigned not null comment 'Sum of the LOCK_TIME column in the events_statements_current table.',"
+                      "SUM_ERRORS BIGINT unsigned not null comment 'Sum of the ERRORS column in the events_statements_current table.',"
+                      "SUM_WARNINGS BIGINT unsigned not null comment 'Sum of the WARNINGS column in the events_statements_current table.',"
+                      "SUM_ROWS_AFFECTED BIGINT unsigned not null comment 'Sum of the ROWS_AFFECTED column in the events_statements_current table.',"
+                      "SUM_ROWS_SENT BIGINT unsigned not null comment 'Sum of the ROWS_SENT column in the events_statements_current table.',"
+                      "SUM_ROWS_EXAMINED BIGINT unsigned not null comment 'Sum of the ROWS_EXAMINED column in the events_statements_current table.',"
+                      "SUM_CREATED_TMP_DISK_TABLES BIGINT unsigned not null comment 'Sum of the CREATED_TMP_DISK_TABLES column in the events_statements_current table.',"
+                      "SUM_CREATED_TMP_TABLES BIGINT unsigned not null comment 'Sum of the CREATED_TMP_TABLES column in the events_statements_current table.',"
+                      "SUM_SELECT_FULL_JOIN BIGINT unsigned not null comment 'Sum of the SELECT_FULL_JOIN column in the events_statements_current table.',"
+                      "SUM_SELECT_FULL_RANGE_JOIN BIGINT unsigned not null comment 'Sum of the SELECT_FULL_RANGE_JOIN column in the events_statements_current table.',"
+                      "SUM_SELECT_RANGE BIGINT unsigned not null comment 'Sum of the SELECT_RANGE column in the events_statements_current table.',"
+                      "SUM_SELECT_RANGE_CHECK BIGINT unsigned not null comment 'Sum of the SELECT_RANGE_CHECK column in the events_statements_current table.',"
+                      "SUM_SELECT_SCAN BIGINT unsigned not null comment 'Sum of the SELECT_SCAN column in the events_statements_current table.',"
+                      "SUM_SORT_MERGE_PASSES BIGINT unsigned not null comment 'Sum of the SORT_MERGE_PASSES column in the events_statements_current table.',"
+                      "SUM_SORT_RANGE BIGINT unsigned not null comment 'Sum of the SORT_RANGE column in the events_statements_current table.',"
+                      "SUM_SORT_ROWS BIGINT unsigned not null comment 'Sum of the SORT_ROWS column in the events_statements_current table.',"
+                      "SUM_SORT_SCAN BIGINT unsigned not null comment 'Sum of the SORT_SCAN column in the events_statements_current table.',"
+                      "SUM_NO_INDEX_USED BIGINT unsigned not null comment 'Sum of the NO_INDEX_USED column in the events_statements_current table.',"
+                      "SUM_NO_GOOD_INDEX_USED BIGINT unsigned not null comment 'Sum of the NO_GOOD_INDEX_USED column in the events_statements_current table.')") }
 };
 
 PFS_engine_table*

storage/perfschema/table_events_stages.cc

@@ -48,16 +48,16 @@ table_events_stages_current::m_share=
   sizeof(PFS_simple_index), /* ref length */
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE events_stages_current("
-                      "THREAD_ID BIGINT unsigned not null,"
-                      "EVENT_ID BIGINT unsigned not null,"
-                      "END_EVENT_ID BIGINT unsigned,"
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "SOURCE VARCHAR(64),"
-                      "TIMER_START BIGINT unsigned,"
-                      "TIMER_END BIGINT unsigned,"
-                      "TIMER_WAIT BIGINT unsigned,"
-                      "NESTING_EVENT_ID BIGINT unsigned,"
-                      "NESTING_EVENT_TYPE ENUM('STATEMENT', 'STAGE', 'WAIT'))") }
+                      "THREAD_ID BIGINT unsigned not null comment 'Thread associated with the event. Together with EVENT_ID uniquely identifies the row.',"
+                      "EVENT_ID BIGINT unsigned not null comment 'Thread''s current event number at the start of the event. Together with THREAD_ID uniquely identifies the row.',"
+                      "END_EVENT_ID BIGINT unsigned comment 'NULL when the event starts, set to the thread''s current event number at the end of the event.',"
+                      "EVENT_NAME VARCHAR(128) not null comment 'Event instrument name and a NAME from the setup_instruments table',"
+                      "SOURCE VARCHAR(64) comment 'Name and line number of the source file containing the instrumented code that produced the event.',"
+                      "TIMER_START BIGINT unsigned comment 'Value in picoseconds when the event timing started or NULL if timing is not collected.',"
+                      "TIMER_END BIGINT unsigned comment 'Value in picoseconds when the event timing ended, or NULL if the event has not ended or timing is not collected.',"
+                      "TIMER_WAIT BIGINT unsigned comment 'Value in picoseconds of the event''s duration or NULL if the event has not ended or timing is not collected.',"
+                      "NESTING_EVENT_ID BIGINT unsigned comment 'EVENT_ID of event within which this event nests.',"
+                      "NESTING_EVENT_TYPE ENUM('STATEMENT', 'STAGE', 'WAIT') comment 'Nesting event type. Either statement, stage or wait.')") }
 };
 
 THR_LOCK table_events_stages_history::m_table_lock;
@@ -75,16 +75,16 @@ table_events_stages_history::m_share=
   sizeof(pos_events_stages_history), /* ref length */
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE events_stages_history("
-                      "THREAD_ID BIGINT unsigned not null,"
-                      "EVENT_ID BIGINT unsigned not null,"
-                      "END_EVENT_ID BIGINT unsigned,"
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "SOURCE VARCHAR(64),"
-                      "TIMER_START BIGINT unsigned,"
-                      "TIMER_END BIGINT unsigned,"
-                      "TIMER_WAIT BIGINT unsigned,"
-                      "NESTING_EVENT_ID BIGINT unsigned,"
-                      "NESTING_EVENT_TYPE ENUM('STATEMENT', 'STAGE', 'WAIT'))") }
+                      "THREAD_ID BIGINT unsigned not null comment 'Thread associated with the event. Together with EVENT_ID uniquely identifies the row.',"
+                      "EVENT_ID BIGINT unsigned not null comment 'Thread''s current event number at the start of the event. Together with THREAD_ID uniquely identifies the row.',"
+                      "END_EVENT_ID BIGINT unsigned comment 'NULL when the event starts, set to the thread''s current event number at the end of the event.',"
+                      "EVENT_NAME VARCHAR(128) not null comment 'Event instrument name and a NAME from the setup_instruments table',"
+                      "SOURCE VARCHAR(64) comment 'Name and line number of the source file containing the instrumented code that produced the event.',"
+                      "TIMER_START BIGINT unsigned comment 'Value in picoseconds when the event timing started or NULL if timing is not collected.',"
+                      "TIMER_END BIGINT unsigned comment 'Value in picoseconds when the event timing ended, or NULL if the event has not ended or timing is not collected.',"
+                      "TIMER_WAIT BIGINT unsigned comment 'Value in picoseconds of the event''s duration or NULL if the event has not ended or timing is not collected.',"
+                      "NESTING_EVENT_ID BIGINT unsigned comment 'EVENT_ID of event within which this event nests.',"
+                      "NESTING_EVENT_TYPE ENUM('STATEMENT', 'STAGE', 'WAIT') comment 'Nesting event type. Either statement, stage or wait.')") }
 };
 
 THR_LOCK table_events_stages_history_long::m_table_lock;
@@ -102,16 +102,16 @@ table_events_stages_history_long::m_share=
   sizeof(PFS_simple_index), /* ref length */
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE events_stages_history_long("
-                      "THREAD_ID BIGINT unsigned not null,"
-                      "EVENT_ID BIGINT unsigned not null,"
-                      "END_EVENT_ID BIGINT unsigned,"
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "SOURCE VARCHAR(64),"
-                      "TIMER_START BIGINT unsigned,"
-                      "TIMER_END BIGINT unsigned,"
-                      "TIMER_WAIT BIGINT unsigned,"
-                      "NESTING_EVENT_ID BIGINT unsigned,"
-                      "NESTING_EVENT_TYPE ENUM('STATEMENT', 'STAGE', 'WAIT'))") }
+                      "THREAD_ID BIGINT unsigned not null comment 'Thread associated with the event. Together with EVENT_ID uniquely identifies the row.',"
+                      "EVENT_ID BIGINT unsigned not null comment 'Thread''s current event number at the start of the event. Together with THREAD_ID uniquely identifies the row.',"
+                      "END_EVENT_ID BIGINT unsigned comment 'NULL when the event starts, set to the thread''s current event number at the end of the event.',"
+                      "EVENT_NAME VARCHAR(128) not null comment 'Event instrument name and a NAME from the setup_instruments table',"
+                      "SOURCE VARCHAR(64) comment 'Name and line number of the source file containing the instrumented code that produced the event.',"
+                      "TIMER_START BIGINT unsigned comment 'Value in picoseconds when the event timing started or NULL if timing is not collected.',"
+                      "TIMER_END BIGINT unsigned comment 'Value in picoseconds when the event timing ended, or NULL if the event has not ended or timing is not collected.',"
+                      "TIMER_WAIT BIGINT unsigned comment 'Value in picoseconds of the event''s duration or NULL if the event has not ended or timing is not collected.',"
+                      "NESTING_EVENT_ID BIGINT unsigned comment 'EVENT_ID of event within which this event nests.',"
+                      "NESTING_EVENT_TYPE ENUM('STATEMENT', 'STAGE', 'WAIT') comment 'Nesting event type. Either statement, stage or wait.')") }
 };
 
 table_events_stages_common::table_events_stages_common

storage/perfschema/table_events_statements.cc

@@ -51,46 +51,46 @@ table_events_statements_current::m_share=
   sizeof(pos_events_statements_current), /* ref length */
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE events_statements_current("
-                      "THREAD_ID BIGINT unsigned not null,"
-                      "EVENT_ID BIGINT unsigned not null,"
-                      "END_EVENT_ID BIGINT unsigned,"
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "SOURCE VARCHAR(64),"
-                      "TIMER_START BIGINT unsigned,"
-                      "TIMER_END BIGINT unsigned,"
-                      "TIMER_WAIT BIGINT unsigned,"
-                      "LOCK_TIME bigint unsigned not null,"
-                      "SQL_TEXT LONGTEXT,"
-                      "DIGEST VARCHAR(32),"
-                      "DIGEST_TEXT LONGTEXT,"
-                      "CURRENT_SCHEMA VARCHAR(64),"
-                      "OBJECT_TYPE VARCHAR(64),"
-                      "OBJECT_SCHEMA VARCHAR(64),"
-                      "OBJECT_NAME VARCHAR(64),"
-                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned,"
-                      "MYSQL_ERRNO INTEGER,"
-                      "RETURNED_SQLSTATE VARCHAR(5),"
-                      "MESSAGE_TEXT VARCHAR(128),"
-                      "ERRORS BIGINT unsigned not null,"
-                      "WARNINGS BIGINT unsigned not null,"
-                      "ROWS_AFFECTED BIGINT unsigned not null,"
-                      "ROWS_SENT BIGINT unsigned not null,"
-                      "ROWS_EXAMINED BIGINT unsigned not null,"
-                      "CREATED_TMP_DISK_TABLES BIGINT unsigned not null,"
-                      "CREATED_TMP_TABLES BIGINT unsigned not null,"
-                      "SELECT_FULL_JOIN BIGINT unsigned not null,"
-                      "SELECT_FULL_RANGE_JOIN BIGINT unsigned not null,"
-                      "SELECT_RANGE BIGINT unsigned not null,"
-                      "SELECT_RANGE_CHECK BIGINT unsigned not null,"
-                      "SELECT_SCAN BIGINT unsigned not null,"
-                      "SORT_MERGE_PASSES BIGINT unsigned not null,"
-                      "SORT_RANGE BIGINT unsigned not null,"
-                      "SORT_ROWS BIGINT unsigned not null,"
-                      "SORT_SCAN BIGINT unsigned not null,"
-                      "NO_INDEX_USED BIGINT unsigned not null,"
-                      "NO_GOOD_INDEX_USED BIGINT unsigned not null,"
-                      "NESTING_EVENT_ID BIGINT unsigned,"
-                      "NESTING_EVENT_TYPE ENUM('STATEMENT', 'STAGE', 'WAIT'))") }
+                      "THREAD_ID BIGINT unsigned not null comment 'Thread associated with the event. Together with EVENT_ID uniquely identifies the row.',"
+                      "EVENT_ID BIGINT unsigned not null comment 'Thread''s current event number at the start of the event. Together with THREAD_ID uniquely identifies the row.',"
+                      "END_EVENT_ID BIGINT unsigned comment 'NULL when the event starts, set to the thread''s current event number at the end of the event.',"
+                      "EVENT_NAME VARCHAR(128) not null comment 'Event instrument name and a NAME from the setup_instruments table',"
+                      "SOURCE VARCHAR(64) comment 'Name and line number of the source file containing the instrumented code that produced the event.',"
+                      "TIMER_START BIGINT unsigned comment 'Value in picoseconds when the event timing started or NULL if timing is not collected.',"
+                      "TIMER_END BIGINT unsigned comment 'Value in picoseconds when the event timing ended, or NULL if the event has not ended or timing is not collected.',"
+                      "TIMER_WAIT BIGINT unsigned comment 'Value in picoseconds of the event''s duration or NULL if the event has not ended or timing is not collected.',"
+                      "LOCK_TIME bigint unsigned not null comment 'Time in picoseconds spent waiting for locks. The time is calculated in microseconds but stored in picoseconds for compatibility with other timings.',"
+                      "SQL_TEXT LONGTEXT comment 'The SQL statement, or NULL if the command is not associated with an SQL statement.',"
+                      "DIGEST VARCHAR(32) comment 'Statement digest.',"
+                      "DIGEST_TEXT LONGTEXT comment 'Statement digest text.',"
+                      "CURRENT_SCHEMA VARCHAR(64) comment 'Statement''s default database for the statement, or NULL if there was none.',"
+                      "OBJECT_TYPE VARCHAR(64) comment 'Reserved, currently NULL',"
+                      "OBJECT_SCHEMA VARCHAR(64) comment 'Reserved, currently NULL',"
+                      "OBJECT_NAME VARCHAR(64) comment 'Reserved, currently NULL',"
+                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned comment 'Address in memory of the statement object.',"
+                      "MYSQL_ERRNO INTEGER comment 'Error code. See MariaDB Error Codes for a full list.',"
+                      "RETURNED_SQLSTATE VARCHAR(5) comment 'The SQLSTATE value.',"
+                      "MESSAGE_TEXT VARCHAR(128) comment 'Statement error message. See MariaDB Error Codes.',"
+                      "ERRORS BIGINT unsigned not null comment '0 if SQLSTATE signifies completion (starting with 00) or warning (01), otherwise 1.',"
+                      "WARNINGS BIGINT unsigned not null comment 'Number of warnings from the diagnostics area.',"
+                      "ROWS_AFFECTED BIGINT unsigned not null comment 'Number of rows affected the statement affected.',"
+                      "ROWS_SENT BIGINT unsigned not null comment 'Number of rows returned.',"
+                      "ROWS_EXAMINED BIGINT unsigned not null comment 'Number of rows read during the statement''s execution.',"
+                      "CREATED_TMP_DISK_TABLES BIGINT unsigned not null comment 'Number of on-disk temp tables created by the statement.',"
+                      "CREATED_TMP_TABLES BIGINT unsigned not null comment 'Number of temp tables created by the statement.',"
+                      "SELECT_FULL_JOIN BIGINT unsigned not null comment 'Number of joins performed by the statement which did not use an index.',"
+                      "SELECT_FULL_RANGE_JOIN BIGINT unsigned not null comment 'Number of joins performed by the statement which used a range search of the first table.',"
+                      "SELECT_RANGE BIGINT unsigned not null comment 'Number of joins performed by the statement which used a range of the first table.',"
+                      "SELECT_RANGE_CHECK BIGINT unsigned not null comment 'Number of joins without keys performed by the statement that check for key usage after each row.',"
+                      "SELECT_SCAN BIGINT unsigned not null comment 'Number of joins performed by the statement which used a full scan of the first table.',"
+                      "SORT_MERGE_PASSES BIGINT unsigned not null comment 'Number of merge passes by the sort algorithm performed by the statement. If too high, you may need to increase the sort_buffer_size.',"
+                      "SORT_RANGE BIGINT unsigned not null comment 'Number of sorts performed by the statement which used a range.',"
+                      "SORT_ROWS BIGINT unsigned not null comment 'Number of rows sorted by the statement.',"
+                      "SORT_SCAN BIGINT unsigned not null comment 'Number of sorts performed by the statement which used a full table scan.',"
+                      "NO_INDEX_USED BIGINT unsigned not null comment '0 if the statement performed a table scan with an index, 1 if without an index.',"
+                      "NO_GOOD_INDEX_USED BIGINT unsigned not null comment '0 if a good index was found for the statement, 1 if no good index was found. See the Range checked for each record description in the EXPLAIN article.',"
+                      "NESTING_EVENT_ID BIGINT unsigned comment 'Reserved, currently NULL.',"
+                      "NESTING_EVENT_TYPE ENUM('STATEMENT', 'STAGE', 'WAIT') comment 'Reserved, currently NULL.')") }
 };
 
 THR_LOCK table_events_statements_history::m_table_lock;
@@ -108,46 +108,46 @@ table_events_statements_history::m_share=
   sizeof(pos_events_statements_history), /* ref length */
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE events_statements_history("
-                      "THREAD_ID BIGINT unsigned not null,"
-                      "EVENT_ID BIGINT unsigned not null,"
-                      "END_EVENT_ID BIGINT unsigned,"
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "SOURCE VARCHAR(64),"
-                      "TIMER_START BIGINT unsigned,"
-                      "TIMER_END BIGINT unsigned,"
-                      "TIMER_WAIT BIGINT unsigned,"
-                      "LOCK_TIME bigint unsigned not null,"
-                      "SQL_TEXT LONGTEXT,"
-                      "DIGEST VARCHAR(32),"
-                      "DIGEST_TEXT LONGTEXT,"
-                      "CURRENT_SCHEMA VARCHAR(64),"
-                      "OBJECT_TYPE VARCHAR(64),"
-                      "OBJECT_SCHEMA VARCHAR(64),"
-                      "OBJECT_NAME VARCHAR(64),"
-                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned,"
-                      "MYSQL_ERRNO INTEGER,"
-                      "RETURNED_SQLSTATE VARCHAR(5),"
-                      "MESSAGE_TEXT VARCHAR(128),"
-                      "ERRORS BIGINT unsigned not null,"
-                      "WARNINGS BIGINT unsigned not null,"
-                      "ROWS_AFFECTED BIGINT unsigned not null,"
-                      "ROWS_SENT BIGINT unsigned not null,"
-                      "ROWS_EXAMINED BIGINT unsigned not null,"
-                      "CREATED_TMP_DISK_TABLES BIGINT unsigned not null,"
-                      "CREATED_TMP_TABLES BIGINT unsigned not null,"
-                      "SELECT_FULL_JOIN BIGINT unsigned not null,"
-                      "SELECT_FULL_RANGE_JOIN BIGINT unsigned not null,"
-                      "SELECT_RANGE BIGINT unsigned not null,"
-                      "SELECT_RANGE_CHECK BIGINT unsigned not null,"
-                      "SELECT_SCAN BIGINT unsigned not null,"
-                      "SORT_MERGE_PASSES BIGINT unsigned not null,"
-                      "SORT_RANGE BIGINT unsigned not null,"
-                      "SORT_ROWS BIGINT unsigned not null,"
-                      "SORT_SCAN BIGINT unsigned not null,"
-                      "NO_INDEX_USED BIGINT unsigned not null,"
-                      "NO_GOOD_INDEX_USED BIGINT unsigned not null,"
-                      "NESTING_EVENT_ID BIGINT unsigned,"
-                      "NESTING_EVENT_TYPE ENUM('STATEMENT', 'STAGE', 'WAIT'))") }
+                      "THREAD_ID BIGINT unsigned not null comment 'Thread associated with the event. Together with EVENT_ID uniquely identifies the row.',"
+                      "EVENT_ID BIGINT unsigned not null comment 'Thread''s current event number at the start of the event. Together with THREAD_ID uniquely identifies the row.',"
+                      "END_EVENT_ID BIGINT unsigned comment 'NULL when the event starts, set to the thread''s current event number at the end of the event.',"
+                      "EVENT_NAME VARCHAR(128) not null comment 'Event instrument name and a NAME from the setup_instruments table',"
+                      "SOURCE VARCHAR(64) comment 'Name and line number of the source file containing the instrumented code that produced the event.',"
+                      "TIMER_START BIGINT unsigned comment 'Value in picoseconds when the event timing started or NULL if timing is not collected.',"
+                      "TIMER_END BIGINT unsigned comment 'Value in picoseconds when the event timing ended, or NULL if the event has not ended or timing is not collected.',"
+                      "TIMER_WAIT BIGINT unsigned comment 'Value in picoseconds of the event''s duration or NULL if the event has not ended or timing is not collected.',"
+                      "LOCK_TIME bigint unsigned not null comment 'Time in picoseconds spent waiting for locks. The time is calculated in microseconds but stored in picoseconds for compatibility with other timings.',"
+                      "SQL_TEXT LONGTEXT comment 'The SQL statement, or NULL if the command is not associated with an SQL statement.',"
+                      "DIGEST VARCHAR(32) comment 'Statement digest.',"
+                      "DIGEST_TEXT LONGTEXT comment 'Statement digest text.',"
+                      "CURRENT_SCHEMA VARCHAR(64) comment 'Statement''s default database for the statement, or NULL if there was none.',"
+                      "OBJECT_TYPE VARCHAR(64) comment 'Reserved, currently NULL',"
+                      "OBJECT_SCHEMA VARCHAR(64) comment 'Reserved, currently NULL',"
+                      "OBJECT_NAME VARCHAR(64) comment 'Reserved, currently NULL',"
+                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned comment 'Address in memory of the statement object.',"
+                      "MYSQL_ERRNO INTEGER comment 'Error code. See MariaDB Error Codes for a full list.',"
+                      "RETURNED_SQLSTATE VARCHAR(5) comment 'The SQLSTATE value.',"
+                      "MESSAGE_TEXT VARCHAR(128) comment 'Statement error message. See MariaDB Error Codes.',"
+                      "ERRORS BIGINT unsigned not null comment '0 if SQLSTATE signifies completion (starting with 00) or warning (01), otherwise 1.',"
+                      "WARNINGS BIGINT unsigned not null comment 'Number of warnings from the diagnostics area.',"
+                      "ROWS_AFFECTED BIGINT unsigned not null comment 'Number of rows affected the statement affected.',"
+                      "ROWS_SENT BIGINT unsigned not null comment 'Number of rows returned.',"
+                      "ROWS_EXAMINED BIGINT unsigned not null comment 'Number of rows read during the statement''s execution.',"
+                      "CREATED_TMP_DISK_TABLES BIGINT unsigned not null comment 'Number of on-disk temp tables created by the statement.',"
+                      "CREATED_TMP_TABLES BIGINT unsigned not null comment 'Number of temp tables created by the statement.',"
+                      "SELECT_FULL_JOIN BIGINT unsigned not null comment 'Number of joins performed by the statement which did not use an index.',"
+                      "SELECT_FULL_RANGE_JOIN BIGINT unsigned not null comment 'Number of joins performed by the statement which used a range search of the first table.',"
+                      "SELECT_RANGE BIGINT unsigned not null comment 'Number of joins performed by the statement which used a range of the first table.',"
+                      "SELECT_RANGE_CHECK BIGINT unsigned not null comment 'Number of joins without keys performed by the statement that check for key usage after each row.',"
+                      "SELECT_SCAN BIGINT unsigned not null comment 'Number of joins performed by the statement which used a full scan of the first table.',"
+                      "SORT_MERGE_PASSES BIGINT unsigned not null comment 'Number of merge passes by the sort algorithm performed by the statement. If too high, you may need to increase the sort_buffer_size.',"
+                      "SORT_RANGE BIGINT unsigned not null comment 'Number of sorts performed by the statement which used a range.',"
+                      "SORT_ROWS BIGINT unsigned not null comment 'Number of rows sorted by the statement.',"
+                      "SORT_SCAN BIGINT unsigned not null comment 'Number of sorts performed by the statement which used a full table scan.',"
+                      "NO_INDEX_USED BIGINT unsigned not null comment '0 if the statement performed a table scan with an index, 1 if without an index.',"
+                      "NO_GOOD_INDEX_USED BIGINT unsigned not null comment '0 if a good index was found for the statement, 1 if no good index was found. See the Range checked for each record description in the EXPLAIN article.',"
+                      "NESTING_EVENT_ID BIGINT unsigned comment 'Reserved, currently NULL.',"
+                      "NESTING_EVENT_TYPE ENUM('STATEMENT', 'STAGE', 'WAIT') comment 'Reserved, currently NULL.')") }
 };
 
 THR_LOCK table_events_statements_history_long::m_table_lock;
@@ -165,46 +165,46 @@ table_events_statements_history_long::m_share=
   sizeof(PFS_simple_index), /* ref length */
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE events_statements_history_long("
-                      "THREAD_ID BIGINT unsigned not null,"
-                      "EVENT_ID BIGINT unsigned not null,"
-                      "END_EVENT_ID BIGINT unsigned,"
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "SOURCE VARCHAR(64),"
-                      "TIMER_START BIGINT unsigned,"
-                      "TIMER_END BIGINT unsigned,"
-                      "TIMER_WAIT BIGINT unsigned,"
-                      "LOCK_TIME bigint unsigned not null,"
-                      "SQL_TEXT LONGTEXT,"
-                      "DIGEST VARCHAR(32),"
-                      "DIGEST_TEXT LONGTEXT,"
-                      "CURRENT_SCHEMA VARCHAR(64),"
-                      "OBJECT_TYPE VARCHAR(64),"
-                      "OBJECT_SCHEMA VARCHAR(64),"
-                      "OBJECT_NAME VARCHAR(64),"
-                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned,"
-                      "MYSQL_ERRNO INTEGER,"
-                      "RETURNED_SQLSTATE VARCHAR(5),"
-                      "MESSAGE_TEXT VARCHAR(128),"
-                      "ERRORS BIGINT unsigned not null,"
-                      "WARNINGS BIGINT unsigned not null,"
-                      "ROWS_AFFECTED BIGINT unsigned not null,"
-                      "ROWS_SENT BIGINT unsigned not null,"
-                      "ROWS_EXAMINED BIGINT unsigned not null,"
-                      "CREATED_TMP_DISK_TABLES BIGINT unsigned not null,"
-                      "CREATED_TMP_TABLES BIGINT unsigned not null,"
-                      "SELECT_FULL_JOIN BIGINT unsigned not null,"
-                      "SELECT_FULL_RANGE_JOIN BIGINT unsigned not null,"
-                      "SELECT_RANGE BIGINT unsigned not null,"
-                      "SELECT_RANGE_CHECK BIGINT unsigned not null,"
-                      "SELECT_SCAN BIGINT unsigned not null,"
-                      "SORT_MERGE_PASSES BIGINT unsigned not null,"
-                      "SORT_RANGE BIGINT unsigned not null,"
-                      "SORT_ROWS BIGINT unsigned not null,"
-                      "SORT_SCAN BIGINT unsigned not null,"
-                      "NO_INDEX_USED BIGINT unsigned not null,"
-                      "NO_GOOD_INDEX_USED BIGINT unsigned not null,"
-                      "NESTING_EVENT_ID BIGINT unsigned,"
-                      "NESTING_EVENT_TYPE ENUM('STATEMENT', 'STAGE', 'WAIT'))") }
+                      "THREAD_ID BIGINT unsigned not null comment 'Thread associated with the event. Together with EVENT_ID uniquely identifies the row.',"
+                      "EVENT_ID BIGINT unsigned not null comment 'Thread''s current event number at the start of the event. Together with THREAD_ID uniquely identifies the row.',"
+                      "END_EVENT_ID BIGINT unsigned comment 'NULL when the event starts, set to the thread''s current event number at the end of the event.',"
+                      "EVENT_NAME VARCHAR(128) not null comment 'Event instrument name and a NAME from the setup_instruments table',"
+                      "SOURCE VARCHAR(64) comment 'Name and line number of the source file containing the instrumented code that produced the event.',"
+                      "TIMER_START BIGINT unsigned comment 'Value in picoseconds when the event timing started or NULL if timing is not collected.',"
+                      "TIMER_END BIGINT unsigned comment 'Value in picoseconds when the event timing ended, or NULL if the event has not ended or timing is not collected.',"
+                      "TIMER_WAIT BIGINT unsigned comment 'Value in picoseconds of the event''s duration or NULL if the event has not ended or timing is not collected.',"
+                      "LOCK_TIME bigint unsigned not null comment 'Time in picoseconds spent waiting for locks. The time is calculated in microseconds but stored in picoseconds for compatibility with other timings.',"
+                      "SQL_TEXT LONGTEXT comment 'The SQL statement, or NULL if the command is not associated with an SQL statement.',"
+                      "DIGEST VARCHAR(32) comment 'Statement digest.',"
+                      "DIGEST_TEXT LONGTEXT comment 'Statement digest text.',"
+                      "CURRENT_SCHEMA VARCHAR(64) comment 'Statement''s default database for the statement, or NULL if there was none.',"
+                      "OBJECT_TYPE VARCHAR(64) comment 'Reserved, currently NULL',"
+                      "OBJECT_SCHEMA VARCHAR(64) comment 'Reserved, currently NULL',"
+                      "OBJECT_NAME VARCHAR(64) comment 'Reserved, currently NULL',"
+                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned comment 'Address in memory of the statement object.',"
+                      "MYSQL_ERRNO INTEGER comment 'Error code. See MariaDB Error Codes for a full list.',"
+                      "RETURNED_SQLSTATE VARCHAR(5) comment 'The SQLSTATE value.',"
+                      "MESSAGE_TEXT VARCHAR(128) comment 'Statement error message. See MariaDB Error Codes.',"
+                      "ERRORS BIGINT unsigned not null comment '0 if SQLSTATE signifies completion (starting with 00) or warning (01), otherwise 1.',"
+                      "WARNINGS BIGINT unsigned not null comment 'Number of warnings from the diagnostics area.',"
+                      "ROWS_AFFECTED BIGINT unsigned not null comment 'Number of rows affected the statement affected.',"
+                      "ROWS_SENT BIGINT unsigned not null comment 'Number of rows returned.',"
+                      "ROWS_EXAMINED BIGINT unsigned not null comment 'Number of rows read during the statement''s execution.',"
+                      "CREATED_TMP_DISK_TABLES BIGINT unsigned not null comment 'Number of on-disk temp tables created by the statement.',"
+                      "CREATED_TMP_TABLES BIGINT unsigned not null comment 'Number of temp tables created by the statement.',"
+                      "SELECT_FULL_JOIN BIGINT unsigned not null comment 'Number of joins performed by the statement which did not use an index.',"
+                      "SELECT_FULL_RANGE_JOIN BIGINT unsigned not null comment 'Number of joins performed by the statement which used a range search of the first table.',"
+                      "SELECT_RANGE BIGINT unsigned not null comment 'Number of joins performed by the statement which used a range of the first table.',"
+                      "SELECT_RANGE_CHECK BIGINT unsigned not null comment 'Number of joins without keys performed by the statement that check for key usage after each row.',"
+                      "SELECT_SCAN BIGINT unsigned not null comment 'Number of joins performed by the statement which used a full scan of the first table.',"
+                      "SORT_MERGE_PASSES BIGINT unsigned not null comment 'Number of merge passes by the sort algorithm performed by the statement. If too high, you may need to increase the sort_buffer_size.',"
+                      "SORT_RANGE BIGINT unsigned not null comment 'Number of sorts performed by the statement which used a range.',"
+                      "SORT_ROWS BIGINT unsigned not null comment 'Number of rows sorted by the statement.',"
+                      "SORT_SCAN BIGINT unsigned not null comment 'Number of sorts performed by the statement which used a full table scan.',"
+                      "NO_INDEX_USED BIGINT unsigned not null comment '0 if the statement performed a table scan with an index, 1 if without an index.',"
+                      "NO_GOOD_INDEX_USED BIGINT unsigned not null comment '0 if a good index was found for the statement, 1 if no good index was found. See the Range checked for each record description in the EXPLAIN article.',"
+                      "NESTING_EVENT_ID BIGINT unsigned comment 'Reserved, currently NULL.',"
+                      "NESTING_EVENT_TYPE ENUM('STATEMENT', 'STAGE', 'WAIT') comment 'Reserved, currently NULL.')") }
 };
 
 table_events_statements_common::table_events_statements_common

storage/perfschema/table_events_waits.cc

@@ -50,25 +50,25 @@ table_events_waits_current::m_share=
   sizeof(pos_events_waits_current), /* ref length */
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE events_waits_current("
-                      "THREAD_ID BIGINT unsigned not null,"
-                      "EVENT_ID BIGINT unsigned not null,"
-                      "END_EVENT_ID BIGINT unsigned,"
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "SOURCE VARCHAR(64),"
-                      "TIMER_START BIGINT unsigned,"
-                      "TIMER_END BIGINT unsigned,"
-                      "TIMER_WAIT BIGINT unsigned,"
-                      "SPINS INTEGER unsigned,"
-                      "OBJECT_SCHEMA VARCHAR(64),"
-                      "OBJECT_NAME VARCHAR(512),"
-                      "INDEX_NAME VARCHAR(64),"
-                      "OBJECT_TYPE VARCHAR(64),"
-                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned not null,"
-                      "NESTING_EVENT_ID BIGINT unsigned,"
-                      "NESTING_EVENT_TYPE ENUM('STATEMENT', 'STAGE', 'WAIT'),"
-                      "OPERATION VARCHAR(32) not null,"
-                      "NUMBER_OF_BYTES BIGINT,"
-                      "FLAGS INTEGER unsigned)") }
+                      "THREAD_ID BIGINT unsigned not null comment 'Thread associated with the event. Together with EVENT_ID uniquely identifies the row.',"
+                      "EVENT_ID BIGINT unsigned not null comment 'Thread''s current event number at the start of the event. Together with THREAD_ID uniquely identifies the row.',"
+                      "END_EVENT_ID BIGINT unsigned comment 'NULL when the event starts, set to the thread''s current event number at the end of the event.',"
+                      "EVENT_NAME VARCHAR(128) not null comment 'Event instrument name and a NAME from the setup_instruments table',"
+                      "SOURCE VARCHAR(64) comment 'Name and line number of the source file containing the instrumented code that produced the event.',"
+                      "TIMER_START BIGINT unsigned comment 'Value in picoseconds when the event timing started or NULL if timing is not collected.',"
+                      "TIMER_END BIGINT unsigned comment 'Value in picoseconds when the event timing ended, or NULL if the event has not ended or timing is not collected.',"
+                      "TIMER_WAIT BIGINT unsigned comment 'Value in picoseconds of the event''s duration or NULL if the event has not ended or timing is not collected.',"
+                      "SPINS INTEGER unsigned comment 'Number of spin rounds for a mutex, or NULL if spin rounds are not used, or spinning is not instrumented.',"
+                      "OBJECT_SCHEMA VARCHAR(64) comment 'Name of the schema that contains the table for table I/O objects, otherwise NULL for file I/O and synchronization objects.',"
+                      "OBJECT_NAME VARCHAR(512) comment 'File name for file I/O objects, table name for table I/O objects, the socket''s IP:PORT value for a socket object or NULL for a synchronization object.',"
+                      "INDEX_NAME VARCHAR(64) comment 'Name of the index, PRIMARY for the primary key, or NULL for no index used.',"
+                      "OBJECT_TYPE VARCHAR(64) comment 'FILE for a file object, TABLE or TEMPORARY TABLE for a table object, or NULL for a synchronization object.',"
+                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned not null comment 'Address in memory of the object.',"
+                      "NESTING_EVENT_ID BIGINT unsigned comment 'EVENT_ID of event within which this event nests.',"
+                      "NESTING_EVENT_TYPE ENUM('STATEMENT', 'STAGE', 'WAIT') comment 'Nesting event type. Either statement, stage or wait.',"
+                      "OPERATION VARCHAR(32) not null comment 'Operation type, for example read, write or lock',"
+                      "NUMBER_OF_BYTES BIGINT comment 'Number of bytes that the operation read or wrote, or NULL for table I/O waits.',"
+                      "FLAGS INTEGER unsigned comment 'Reserved for use in the future.')") }
 };
 
 THR_LOCK table_events_waits_history::m_table_lock;
@@ -86,25 +86,25 @@ table_events_waits_history::m_share=
   sizeof(pos_events_waits_history), /* ref length */
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE events_waits_history("
-                      "THREAD_ID BIGINT unsigned not null,"
-                      "EVENT_ID BIGINT unsigned not null,"
-                      "END_EVENT_ID BIGINT unsigned,"
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "SOURCE VARCHAR(64),"
-                      "TIMER_START BIGINT unsigned,"
-                      "TIMER_END BIGINT unsigned,"
-                      "TIMER_WAIT BIGINT unsigned,"
-                      "SPINS INTEGER unsigned,"
-                      "OBJECT_SCHEMA VARCHAR(64),"
-                      "OBJECT_NAME VARCHAR(512),"
-                      "INDEX_NAME VARCHAR(64),"
-                      "OBJECT_TYPE VARCHAR(64),"
-                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned not null,"
-                      "NESTING_EVENT_ID BIGINT unsigned,"
-                      "NESTING_EVENT_TYPE ENUM('STATEMENT', 'STAGE', 'WAIT'),"
-                      "OPERATION VARCHAR(32) not null,"
-                      "NUMBER_OF_BYTES BIGINT,"
-                      "FLAGS INTEGER unsigned)") }
+                      "THREAD_ID BIGINT unsigned not null comment 'Thread associated with the event. Together with EVENT_ID uniquely identifies the row.',"
+                      "EVENT_ID BIGINT unsigned not null comment 'Thread''s current event number at the start of the event. Together with THREAD_ID uniquely identifies the row.',"
+                      "END_EVENT_ID BIGINT unsigned comment 'NULL when the event starts, set to the thread''s current event number at the end of the event.',"
+                      "EVENT_NAME VARCHAR(128) not null comment 'Event instrument name and a NAME from the setup_instruments table',"
+                      "SOURCE VARCHAR(64) comment 'Name and line number of the source file containing the instrumented code that produced the event.',"
+                      "TIMER_START BIGINT unsigned comment 'Value in picoseconds when the event timing started or NULL if timing is not collected.',"
+                      "TIMER_END BIGINT unsigned comment 'Value in picoseconds when the event timing ended, or NULL if the event has not ended or timing is not collected.',"
+                      "TIMER_WAIT BIGINT unsigned comment 'Value in picoseconds of the event''s duration or NULL if the event has not ended or timing is not collected.',"
+                      "SPINS INTEGER unsigned comment 'Number of spin rounds for a mutex, or NULL if spin rounds are not used, or spinning is not instrumented.',"
+                      "OBJECT_SCHEMA VARCHAR(64) comment 'Name of the schema that contains the table for table I/O objects, otherwise NULL for file I/O and synchronization objects.',"
+                      "OBJECT_NAME VARCHAR(512) comment 'File name for file I/O objects, table name for table I/O objects, the socket''s IP:PORT value for a socket object or NULL for a synchronization object.',"
+                      "INDEX_NAME VARCHAR(64) comment 'Name of the index, PRIMARY for the primary key, or NULL for no index used.',"
+                      "OBJECT_TYPE VARCHAR(64) comment 'FILE for a file object, TABLE or TEMPORARY TABLE for a table object, or NULL for a synchronization object.',"
+                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned not null comment 'Address in memory of the object.',"
+                      "NESTING_EVENT_ID BIGINT unsigned comment 'EVENT_ID of event within which this event nests.',"
+                      "NESTING_EVENT_TYPE ENUM('STATEMENT', 'STAGE', 'WAIT') comment 'Nesting event type. Either statement, stage or wait.',"
+                      "OPERATION VARCHAR(32) not null comment 'Operation type, for example read, write or lock',"
+                      "NUMBER_OF_BYTES BIGINT comment 'Number of bytes that the operation read or wrote, or NULL for table I/O waits.',"
+                      "FLAGS INTEGER unsigned comment 'Reserved for use in the future.')") }
 };
 
 THR_LOCK table_events_waits_history_long::m_table_lock;
@@ -122,25 +122,25 @@ table_events_waits_history_long::m_share=
   sizeof(PFS_simple_index), /* ref length */
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE events_waits_history_long("
-                      "THREAD_ID BIGINT unsigned not null,"
-                      "EVENT_ID BIGINT unsigned not null,"
-                      "END_EVENT_ID BIGINT unsigned,"
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "SOURCE VARCHAR(64),"
-                      "TIMER_START BIGINT unsigned,"
-                      "TIMER_END BIGINT unsigned,"
-                      "TIMER_WAIT BIGINT unsigned,"
-                      "SPINS INTEGER unsigned,"
-                      "OBJECT_SCHEMA VARCHAR(64),"
-                      "OBJECT_NAME VARCHAR(512),"
-                      "INDEX_NAME VARCHAR(64),"
-                      "OBJECT_TYPE VARCHAR(64),"
-                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned not null,"
-                      "NESTING_EVENT_ID BIGINT unsigned,"
-                      "NESTING_EVENT_TYPE ENUM('STATEMENT', 'STAGE', 'WAIT'),"
-                      "OPERATION VARCHAR(32) not null,"
-                      "NUMBER_OF_BYTES BIGINT,"
-                      "FLAGS INTEGER unsigned)") }
+                      "THREAD_ID BIGINT unsigned not null comment 'Thread associated with the event. Together with EVENT_ID uniquely identifies the row.',"
+                      "EVENT_ID BIGINT unsigned not null comment 'Thread''s current event number at the start of the event. Together with THREAD_ID uniquely identifies the row.',"
+                      "END_EVENT_ID BIGINT unsigned comment 'NULL when the event starts, set to the thread''s current event number at the end of the event.',"
+                      "EVENT_NAME VARCHAR(128) not null comment 'Event instrument name and a NAME from the setup_instruments table',"
+                      "SOURCE VARCHAR(64) comment 'Name and line number of the source file containing the instrumented code that produced the event.',"
+                      "TIMER_START BIGINT unsigned comment 'Value in picoseconds when the event timing started or NULL if timing is not collected.',"
+                      "TIMER_END BIGINT unsigned comment 'Value in picoseconds when the event timing ended, or NULL if the event has not ended or timing is not collected.',"
+                      "TIMER_WAIT BIGINT unsigned comment 'Value in picoseconds of the event''s duration or NULL if the event has not ended or timing is not collected.',"
+                      "SPINS INTEGER unsigned comment 'Number of spin rounds for a mutex, or NULL if spin rounds are not used, or spinning is not instrumented.',"
+                      "OBJECT_SCHEMA VARCHAR(64) comment 'Name of the schema that contains the table for table I/O objects, otherwise NULL for file I/O and synchronization objects.',"
+                      "OBJECT_NAME VARCHAR(512) comment 'File name for file I/O objects, table name for table I/O objects, the socket''s IP:PORT value for a socket object or NULL for a synchronization object.',"
+                      "INDEX_NAME VARCHAR(64) comment 'Name of the index, PRIMARY for the primary key, or NULL for no index used.',"
+                      "OBJECT_TYPE VARCHAR(64) comment 'FILE for a file object, TABLE or TEMPORARY TABLE for a table object, or NULL for a synchronization object.',"
+                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned not null comment 'Address in memory of the object.',"
+                      "NESTING_EVENT_ID BIGINT unsigned comment 'EVENT_ID of event within which this event nests.',"
+                      "NESTING_EVENT_TYPE ENUM('STATEMENT', 'STAGE', 'WAIT') comment 'Nesting event type. Either statement, stage or wait.',"
+                      "OPERATION VARCHAR(32) not null comment 'Operation type, for example read, write or lock',"
+                      "NUMBER_OF_BYTES BIGINT comment 'Number of bytes that the operation read or wrote, or NULL for table I/O waits.',"
+                      "FLAGS INTEGER unsigned comment 'Reserved for use in the future.')") }
 };
 
 table_events_waits_common::table_events_waits_common

storage/perfschema/table_events_waits_summary.cc

@@ -48,13 +48,13 @@ table_events_waits_summary_by_instance::m_share=
   sizeof(pos_all_instr),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE events_waits_summary_by_instance("
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned not null,"
-                      "COUNT_STAR BIGINT unsigned not null,"
-                      "SUM_TIMER_WAIT BIGINT unsigned not null,"
-                      "MIN_TIMER_WAIT BIGINT unsigned not null,"
-                      "AVG_TIMER_WAIT BIGINT unsigned not null,"
-                      "MAX_TIMER_WAIT BIGINT unsigned not null)") }
+                      "EVENT_NAME VARCHAR(128) not null comment 'Event name. Used together with OBJECT_INSTANCE_BEGIN for grouping events.',"
+                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned not null comment 'If an instrument creates multiple instances, each instance has a unique OBJECT_INSTANCE_BEGIN value to allow for grouping by instance.',"
+                      "COUNT_STAR BIGINT unsigned not null comment 'Number of summarized events',"
+                      "SUM_TIMER_WAIT BIGINT unsigned not null comment 'Total wait time of the summarized events that are timed.',"
+                      "MIN_TIMER_WAIT BIGINT unsigned not null comment 'Minimum wait time of the summarized events that are timed.',"
+                      "AVG_TIMER_WAIT BIGINT unsigned not null comment 'Average wait time of the summarized events that are timed.',"
+                      "MAX_TIMER_WAIT BIGINT unsigned not null comment 'Maximum wait time of the summarized events that are timed.')") }
 };
 
 PFS_engine_table* table_events_waits_summary_by_instance::create(void)

storage/perfschema/table_ews_by_account_by_event_name.cc

@@ -49,14 +49,14 @@ table_ews_by_account_by_event_name::m_share=
   sizeof(pos_ews_by_account_by_event_name),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE events_waits_summary_by_account_by_event_name("
-                      "USER CHAR(" STRINGIFY_ARG(USERNAME_CHAR_LENGTH) ") collate utf8_bin default null,"
-                      "HOST CHAR(" STRINGIFY_ARG(HOSTNAME_LENGTH) ") collate utf8_bin default null,"
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "COUNT_STAR BIGINT unsigned not null,"
-                      "SUM_TIMER_WAIT BIGINT unsigned not null,"
-                      "MIN_TIMER_WAIT BIGINT unsigned not null,"
-                      "AVG_TIMER_WAIT BIGINT unsigned not null,"
-                      "MAX_TIMER_WAIT BIGINT unsigned not null)") }
+                      "USER CHAR(" STRINGIFY_ARG(USERNAME_CHAR_LENGTH) ") collate utf8_bin default null comment 'User. Used together with HOST and EVENT_NAME for grouping events.',"
+                      "HOST CHAR(" STRINGIFY_ARG(HOSTNAME_LENGTH) ") collate utf8_bin default null comment 'Host. Used together with USER and EVENT_NAME for grouping events.',"
+                      "EVENT_NAME VARCHAR(128) not null comment 'Event name. Used together with USER and HOST for grouping events.',"
+                      "COUNT_STAR BIGINT unsigned not null comment 'Number of summarized events',"
+                      "SUM_TIMER_WAIT BIGINT unsigned not null comment 'Total wait time of the summarized events that are timed.',"
+                      "MIN_TIMER_WAIT BIGINT unsigned not null comment 'Minimum wait time of the summarized events that are timed.',"
+                      "AVG_TIMER_WAIT BIGINT unsigned not null comment 'Average wait time of the summarized events that are timed.',"
+                      "MAX_TIMER_WAIT BIGINT unsigned not null comment 'Maximum wait time of the summarized events that are timed.')") }
 };
 
 PFS_engine_table*

storage/perfschema/table_ews_by_host_by_event_name.cc

@@ -50,13 +50,13 @@ table_ews_by_host_by_event_name::m_share=
   sizeof(pos_ews_by_host_by_event_name),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE events_waits_summary_by_host_by_event_name("
-                      "HOST CHAR(" STRINGIFY_ARG(HOSTNAME_LENGTH) ") collate utf8_bin default null,"
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "COUNT_STAR BIGINT unsigned not null,"
-                      "SUM_TIMER_WAIT BIGINT unsigned not null,"
-                      "MIN_TIMER_WAIT BIGINT unsigned not null,"
-                      "AVG_TIMER_WAIT BIGINT unsigned not null,"
-                      "MAX_TIMER_WAIT BIGINT unsigned not null)") }
+                      "HOST CHAR(" STRINGIFY_ARG(HOSTNAME_LENGTH) ") collate utf8_bin default null comment 'Host. Used together with EVENT_NAME for grouping events.',"
+                      "EVENT_NAME VARCHAR(128) not null comment 'Event name. Used together with USER and HOST for grouping events.',"
+                      "COUNT_STAR BIGINT unsigned not null comment 'Number of summarized events',"
+                      "SUM_TIMER_WAIT BIGINT unsigned not null comment 'Total wait time of the summarized events that are timed.',"
+                      "MIN_TIMER_WAIT BIGINT unsigned not null comment 'Minimum wait time of the summarized events that are timed.',"
+                      "AVG_TIMER_WAIT BIGINT unsigned not null comment 'Average wait time of the summarized events that are timed.',"
+                      "MAX_TIMER_WAIT BIGINT unsigned not null comment 'Maximum wait time of the summarized events that are timed.' )") }
 };
 
 PFS_engine_table*

storage/perfschema/table_ews_by_thread_by_event_name.cc

@@ -49,13 +49,13 @@ table_ews_by_thread_by_event_name::m_share=
   sizeof(pos_ews_by_thread_by_event_name),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE events_waits_summary_by_thread_by_event_name("
-                      "THREAD_ID BIGINT unsigned not null,"
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "COUNT_STAR BIGINT unsigned not null,"
-                      "SUM_TIMER_WAIT BIGINT unsigned not null,"
-                      "MIN_TIMER_WAIT BIGINT unsigned not null,"
-                      "AVG_TIMER_WAIT BIGINT unsigned not null,"
-                      "MAX_TIMER_WAIT BIGINT unsigned not null)") }
+                      "THREAD_ID BIGINT unsigned not null comment 'Thread associated with the event. Together with EVENT_NAME uniquely identifies the row.',"
+                      "EVENT_NAME VARCHAR(128) not null comment 'Event name. Used together with THREAD_ID for grouping events.',"
+                      "COUNT_STAR BIGINT unsigned not null comment 'Number of summarized events',"
+                      "SUM_TIMER_WAIT BIGINT unsigned not null comment 'Total wait time of the summarized events that are timed.',"
+                      "MIN_TIMER_WAIT BIGINT unsigned not null comment 'Minimum wait time of the summarized events that are timed.',"
+                      "AVG_TIMER_WAIT BIGINT unsigned not null comment 'Average wait time of the summarized events that are timed.',"
+                      "MAX_TIMER_WAIT BIGINT unsigned not null comment 'Maximum wait time of the summarized events that are timed.')") }
 };
 
 PFS_engine_table*

storage/perfschema/table_ews_by_user_by_event_name.cc

@@ -50,13 +50,13 @@ table_ews_by_user_by_event_name::m_share=
   sizeof(pos_ews_by_user_by_event_name),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE events_waits_summary_by_user_by_event_name("
-                      "USER CHAR(" STRINGIFY_ARG(USERNAME_CHAR_LENGTH) ") collate utf8_bin default null,"
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "COUNT_STAR BIGINT unsigned not null,"
-                      "SUM_TIMER_WAIT BIGINT unsigned not null,"
-                      "MIN_TIMER_WAIT BIGINT unsigned not null,"
-                      "AVG_TIMER_WAIT BIGINT unsigned not null,"
-                      "MAX_TIMER_WAIT BIGINT unsigned not null)") }
+                      "USER CHAR(" STRINGIFY_ARG(USERNAME_CHAR_LENGTH) ") collate utf8_bin default null comment 'User. Used together with EVENT_NAME for grouping events.',"
+                      "EVENT_NAME VARCHAR(128) not null comment 'Event name. Used together with USER for grouping events.',"
+                      "COUNT_STAR BIGINT unsigned not null comment 'Number of summarized events',"
+                      "SUM_TIMER_WAIT BIGINT unsigned not null comment 'Total wait time of the summarized events that are timed.',"
+                      "MIN_TIMER_WAIT BIGINT unsigned not null comment 'Minimum wait time of the summarized events that are timed.',"
+                      "AVG_TIMER_WAIT BIGINT unsigned not null comment 'Average wait time of the summarized events that are timed.',"
+                      "MAX_TIMER_WAIT BIGINT unsigned not null comment 'Maximum wait time of the summarized events that are timed.')") }
 };
 
 PFS_engine_table*

storage/perfschema/table_ews_global_by_event_name.cc

@@ -51,12 +51,12 @@ table_ews_global_by_event_name::m_share=
   sizeof(pos_ews_global_by_event_name),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE events_waits_summary_global_by_event_name("
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "COUNT_STAR BIGINT unsigned not null,"
-                      "SUM_TIMER_WAIT BIGINT unsigned not null,"
-                      "MIN_TIMER_WAIT BIGINT unsigned not null,"
-                      "AVG_TIMER_WAIT BIGINT unsigned not null,"
-                      "MAX_TIMER_WAIT BIGINT unsigned not null)") }
+                      "EVENT_NAME VARCHAR(128) not null comment 'Event name.',"
+                      "COUNT_STAR BIGINT unsigned not null comment 'Number of summarized events',"
+                      "SUM_TIMER_WAIT BIGINT unsigned not null comment 'Total wait time of the summarized events that are timed.',"
+                      "MIN_TIMER_WAIT BIGINT unsigned not null comment 'Minimum wait time of the summarized events that are timed.',"
+                      "AVG_TIMER_WAIT BIGINT unsigned not null comment 'Average wait time of the summarized events that are timed.',"
+                      "MAX_TIMER_WAIT BIGINT unsigned not null comment 'Maximum wait time of the summarized events that are timed.')") }
 };
 
 PFS_engine_table*

storage/perfschema/table_file_instances.cc

@@ -48,9 +48,9 @@ table_file_instances::m_share=
   sizeof(PFS_simple_index),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE file_instances("
-                      "FILE_NAME VARCHAR(512) not null,"
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "OPEN_COUNT INTEGER unsigned not null)") }
+                      "FILE_NAME VARCHAR(512) not null comment 'File name.',"
+                      "EVENT_NAME VARCHAR(128) not null comment 'Instrument name associated with the file.',"
+                      "OPEN_COUNT INTEGER unsigned not null comment 'Open handles on the file. A value of greater than zero means that the file is currently open.')") }
 };
 
 PFS_engine_table* table_file_instances::create(void)

storage/perfschema/table_file_summary_by_event_name.cc

@@ -49,29 +49,29 @@ table_file_summary_by_event_name::m_share=
   sizeof(PFS_simple_index),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE file_summary_by_event_name("
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "COUNT_STAR BIGINT unsigned not null,"
-                      "SUM_TIMER_WAIT BIGINT unsigned not null,"
-                      "MIN_TIMER_WAIT BIGINT unsigned not null,"
-                      "AVG_TIMER_WAIT BIGINT unsigned not null,"
-                      "MAX_TIMER_WAIT BIGINT unsigned not null,"
-                      "COUNT_READ BIGINT unsigned not null,"
-                      "SUM_TIMER_READ BIGINT unsigned not null,"
-                      "MIN_TIMER_READ BIGINT unsigned not null,"
-                      "AVG_TIMER_READ BIGINT unsigned not null,"
-                      "MAX_TIMER_READ BIGINT unsigned not null,"
-                      "SUM_NUMBER_OF_BYTES_READ BIGINT not null,"
-                      "COUNT_WRITE BIGINT unsigned not null,"
-                      "SUM_TIMER_WRITE BIGINT unsigned not null,"
-                      "MIN_TIMER_WRITE BIGINT unsigned not null,"
-                      "AVG_TIMER_WRITE BIGINT unsigned not null,"
-                      "MAX_TIMER_WRITE BIGINT unsigned not null,"
-                      "SUM_NUMBER_OF_BYTES_WRITE BIGINT not null,"
-                      "COUNT_MISC BIGINT unsigned not null,"
-                      "SUM_TIMER_MISC BIGINT unsigned not null,"
-                      "MIN_TIMER_MISC BIGINT unsigned not null,"
-                      "AVG_TIMER_MISC BIGINT unsigned not null,"
-                      "MAX_TIMER_MISC BIGINT unsigned not null)") }
+                      "EVENT_NAME VARCHAR(128) not null comment 'Event name.',"
+                      "COUNT_STAR BIGINT unsigned not null comment 'Number of summarized events',"
+                      "SUM_TIMER_WAIT BIGINT unsigned not null comment 'Total wait time of the summarized events that are timed.',"
+                      "MIN_TIMER_WAIT BIGINT unsigned not null comment 'Minimum wait time of the summarized events that are timed.',"
+                      "AVG_TIMER_WAIT BIGINT unsigned not null comment 'Average wait time of the summarized events that are timed.',"
+                      "MAX_TIMER_WAIT BIGINT unsigned not null comment 'Maximum wait time of the summarized events that are timed.',"
+                      "COUNT_READ BIGINT unsigned not null comment 'Number of all read operations, including FGETS, FGETC, FREAD, and READ.',"
+                      "SUM_TIMER_READ BIGINT unsigned not null comment 'Total wait time of all read operations that are timed.',"
+                      "MIN_TIMER_READ BIGINT unsigned not null comment 'Minimum wait time of all read operations that are timed.',"
+                      "AVG_TIMER_READ BIGINT unsigned not null comment 'Average wait time of all read operations that are timed.',"
+                      "MAX_TIMER_READ BIGINT unsigned not null comment 'Maximum wait time of all read operations that are timed.',"
+                      "SUM_NUMBER_OF_BYTES_READ BIGINT not null comment 'Bytes read by read operations.',"
+                      "COUNT_WRITE BIGINT unsigned not null comment 'Number of all write operations, including FPUTS, FPUTC, FPRINTF, VFPRINTF, FWRITE, and PWRITE.',"
+                      "SUM_TIMER_WRITE BIGINT unsigned not null comment 'Total wait time of all write operations that are timed.',"
+                      "MIN_TIMER_WRITE BIGINT unsigned not null comment 'Minimum wait time of all write operations that are timed.',"
+                      "AVG_TIMER_WRITE BIGINT unsigned not null comment 'Average wait time of all write operations that are timed.',"
+                      "MAX_TIMER_WRITE BIGINT unsigned not null comment 'Maximum wait time of all write operations that are timed.',"
+                      "SUM_NUMBER_OF_BYTES_WRITE BIGINT not null comment 'Bytes written by write operations.',"
+                      "COUNT_MISC BIGINT unsigned not null comment 'Number of all miscellaneous operations not counted above, including CREATE, DELETE, OPEN, CLOSE, STREAM_OPEN, STREAM_CLOSE, SEEK, TELL, FLUSH, STAT, FSTAT, CHSIZE, RENAME, and SYNC.',"
+                      "SUM_TIMER_MISC BIGINT unsigned not null comment 'Total wait time of all miscellaneous operations that are timed.',"
+                      "MIN_TIMER_MISC BIGINT unsigned not null comment 'Minimum wait time of all miscellaneous operations that are timed.',"
+                      "AVG_TIMER_MISC BIGINT unsigned not null comment 'Average wait time of all miscellaneous operations that are timed.',"
+                      "MAX_TIMER_MISC BIGINT unsigned not null comment 'Maximum wait time of all miscellaneous operations that are timed.')") }
 };
 
 PFS_engine_table* table_file_summary_by_event_name::create(void)

storage/perfschema/table_file_summary_by_instance.cc

@@ -48,31 +48,31 @@ table_file_summary_by_instance::m_share=
   sizeof(PFS_simple_index),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE file_summary_by_instance("
-                      "FILE_NAME VARCHAR(512) not null,"
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned not null,"
-                      "COUNT_STAR BIGINT unsigned not null,"
-                      "SUM_TIMER_WAIT BIGINT unsigned not null,"
-                      "MIN_TIMER_WAIT BIGINT unsigned not null,"
-                      "AVG_TIMER_WAIT BIGINT unsigned not null,"
-                      "MAX_TIMER_WAIT BIGINT unsigned not null,"
-                      "COUNT_READ BIGINT unsigned not null,"
-                      "SUM_TIMER_READ BIGINT unsigned not null,"
-                      "MIN_TIMER_READ BIGINT unsigned not null,"
-                      "AVG_TIMER_READ BIGINT unsigned not null,"
-                      "MAX_TIMER_READ BIGINT unsigned not null,"
-                      "SUM_NUMBER_OF_BYTES_READ BIGINT not null,"
-                      "COUNT_WRITE BIGINT unsigned not null,"
-                      "SUM_TIMER_WRITE BIGINT unsigned not null,"
-                      "MIN_TIMER_WRITE BIGINT unsigned not null,"
-                      "AVG_TIMER_WRITE BIGINT unsigned not null,"
-                      "MAX_TIMER_WRITE BIGINT unsigned not null,"
-                      "SUM_NUMBER_OF_BYTES_WRITE BIGINT not null,"
-                      "COUNT_MISC BIGINT unsigned not null,"
-                      "SUM_TIMER_MISC BIGINT unsigned not null,"
-                      "MIN_TIMER_MISC BIGINT unsigned not null,"
-                      "AVG_TIMER_MISC BIGINT unsigned not null,"
-                      "MAX_TIMER_MISC BIGINT unsigned not null)") }
+                      "FILE_NAME VARCHAR(512) not null comment 'File name.',"
+                      "EVENT_NAME VARCHAR(128) not null comment 'Event name.',"
+                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned not null comment 'Address in memory. Together with FILE_NAME and EVENT_NAME uniquely identifies a row.',"
+                      "COUNT_STAR BIGINT unsigned not null comment 'Number of summarized events',"
+                      "SUM_TIMER_WAIT BIGINT unsigned not null comment 'Total wait time of the summarized events that are timed.',"
+                      "MIN_TIMER_WAIT BIGINT unsigned not null comment 'Minimum wait time of the summarized events that are timed.',"
+                      "AVG_TIMER_WAIT BIGINT unsigned not null comment 'Average wait time of the summarized events that are timed.',"
+                      "MAX_TIMER_WAIT BIGINT unsigned not null comment 'Maximum wait time of the summarized events that are timed.',"
+                      "COUNT_READ BIGINT unsigned not null comment 'Number of all read operations, including FGETS, FGETC, FREAD, and READ.',"
+                      "SUM_TIMER_READ BIGINT unsigned not null comment 'Total wait time of all read operations that are timed.',"
+                      "MIN_TIMER_READ BIGINT unsigned not null comment 'Minimum wait time of all read operations that are timed.',"
+                      "AVG_TIMER_READ BIGINT unsigned not null comment 'Average wait time of all read operations that are timed.',"
+                      "MAX_TIMER_READ BIGINT unsigned not null comment 'Maximum wait time of all read operations that are timed.',"
+                      "SUM_NUMBER_OF_BYTES_READ BIGINT not null comment 'Bytes read by read operations.',"
+                      "COUNT_WRITE BIGINT unsigned not null comment 'Number of all write operations, including FPUTS, FPUTC, FPRINTF, VFPRINTF, FWRITE, and PWRITE.',"
+                      "SUM_TIMER_WRITE BIGINT unsigned not null comment 'Total wait time of all write operations that are timed.',"
+                      "MIN_TIMER_WRITE BIGINT unsigned not null comment 'Minimum wait time of all write operations that are timed.',"
+                      "AVG_TIMER_WRITE BIGINT unsigned not null comment 'Average wait time of all write operations that are timed.',"
+                      "MAX_TIMER_WRITE BIGINT unsigned not null comment 'Maximum wait time of all write operations that are timed.',"
+                      "SUM_NUMBER_OF_BYTES_WRITE BIGINT not null comment 'Bytes written by write operations.',"
+                      "COUNT_MISC BIGINT unsigned not null comment 'Number of all miscellaneous operations not counted above, including CREATE, DELETE, OPEN, CLOSE, STREAM_OPEN, STREAM_CLOSE, SEEK, TELL, FLUSH, STAT, FSTAT, CHSIZE, RENAME, and SYNC.',"
+                      "SUM_TIMER_MISC BIGINT unsigned not null comment 'Total wait time of all miscellaneous operations that are timed.',"
+                      "MIN_TIMER_MISC BIGINT unsigned not null comment 'Minimum wait time of all miscellaneous operations that are timed.',"
+                      "AVG_TIMER_MISC BIGINT unsigned not null comment 'Average wait time of all miscellaneous operations that are timed.',"
+                      "MAX_TIMER_MISC BIGINT unsigned not null comment 'Maximum wait time of all miscellaneous operations that are timed.')") }
 };
 
 PFS_engine_table* table_file_summary_by_instance::create(void)

storage/perfschema/table_host_cache.cc

@@ -45,35 +45,35 @@ table_host_cache::m_share=
   sizeof(PFS_simple_index), /* ref length */
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE host_cache("
-                      "IP VARCHAR(64) not null,"
-                      "HOST VARCHAR(255) collate utf8_bin,"
-                      "HOST_VALIDATED ENUM ('YES', 'NO') not null,"
-                      "SUM_CONNECT_ERRORS BIGINT not null,"
-                      "COUNT_HOST_BLOCKED_ERRORS BIGINT not null,"
-                      "COUNT_NAMEINFO_TRANSIENT_ERRORS BIGINT not null,"
-                      "COUNT_NAMEINFO_PERMANENT_ERRORS BIGINT not null,"
-                      "COUNT_FORMAT_ERRORS BIGINT not null,"
-                      "COUNT_ADDRINFO_TRANSIENT_ERRORS BIGINT not null,"
-                      "COUNT_ADDRINFO_PERMANENT_ERRORS BIGINT not null,"
-                      "COUNT_FCRDNS_ERRORS BIGINT not null,"
-                      "COUNT_HOST_ACL_ERRORS BIGINT not null,"
-                      "COUNT_NO_AUTH_PLUGIN_ERRORS BIGINT not null,"
-                      "COUNT_AUTH_PLUGIN_ERRORS BIGINT not null,"
-                      "COUNT_HANDSHAKE_ERRORS BIGINT not null,"
-                      "COUNT_PROXY_USER_ERRORS BIGINT not null,"
-                      "COUNT_PROXY_USER_ACL_ERRORS BIGINT not null,"
-                      "COUNT_AUTHENTICATION_ERRORS BIGINT not null,"
-                      "COUNT_SSL_ERRORS BIGINT not null,"
-                      "COUNT_MAX_USER_CONNECTIONS_ERRORS BIGINT not null,"
-                      "COUNT_MAX_USER_CONNECTIONS_PER_HOUR_ERRORS BIGINT not null,"
-                      "COUNT_DEFAULT_DATABASE_ERRORS BIGINT not null,"
-                      "COUNT_INIT_CONNECT_ERRORS BIGINT not null,"
-                      "COUNT_LOCAL_ERRORS BIGINT not null,"
-                      "COUNT_UNKNOWN_ERRORS BIGINT not null,"
-                      "FIRST_SEEN TIMESTAMP(0) NOT NULL default 0,"
-                      "LAST_SEEN TIMESTAMP(0) NOT NULL default 0,"
-                      "FIRST_ERROR_SEEN TIMESTAMP(0) null default 0,"
-                      "LAST_ERROR_SEEN TIMESTAMP(0) null default 0)") }
+                      "IP VARCHAR(64) not null comment 'Client IP address.',"
+                      "HOST VARCHAR(255) collate utf8_bin comment 'IP''s resolved DNS host name, or NULL if unknown.',"
+                      "HOST_VALIDATED ENUM ('YES', 'NO') not null comment 'YES if the IP-to-host DNS lookup was successful, and the HOST column can be used to avoid DNS calls, or NO if unsuccessful, in which case DNS lookup is performed for each connect until either successful or a permanent error.',"
+                      "SUM_CONNECT_ERRORS BIGINT not null comment 'Number of connection errors. Counts only protocol handshake errors for hosts that passed validation. These errors count towards max_connect_errors.',"
+                      "COUNT_HOST_BLOCKED_ERRORS BIGINT not null comment 'Number of blocked connections because SUM_CONNECT_ERRORS exceeded the max_connect_errors system variable.',"
+                      "COUNT_NAMEINFO_TRANSIENT_ERRORS BIGINT not null comment 'Number of transient errors during IP-to-host DNS lookups.',"
+                      "COUNT_NAMEINFO_PERMANENT_ERRORS BIGINT not null comment 'Number of permanent errors during IP-to-host DNS lookups.',"
+                      "COUNT_FORMAT_ERRORS BIGINT not null comment 'Number of host name format errors, for example a numeric host column.',"
+                      "COUNT_ADDRINFO_TRANSIENT_ERRORS BIGINT not null comment 'Number of transient errors during host-to-IP reverse DNS lookups.',"
+                      "COUNT_ADDRINFO_PERMANENT_ERRORS BIGINT not null comment 'Number of permanent errors during host-to-IP reverse DNS lookups.',"
+                      "COUNT_FCRDNS_ERRORS BIGINT not null comment 'Number of forward-confirmed reverse DNS errors, which occur when IP-to-host DNS lookup does not match the originating IP address.',"
+                      "COUNT_HOST_ACL_ERRORS BIGINT not null comment 'Number of errors occurring because no user from the host is permitted to log in. These attempts return error code 1130 ER_HOST_NOT_PRIVILEGED and do not proceed to username and password authentication.',"
+                      "COUNT_NO_AUTH_PLUGIN_ERRORS BIGINT not null comment 'Number of errors due to requesting an authentication plugin that was not available. This can be due to the plugin never having been loaded, or the load attempt failing.',"
+                      "COUNT_AUTH_PLUGIN_ERRORS BIGINT not null comment 'Number of errors reported by an authentication plugin. Plugins can increment COUNT_AUTHENTICATION_ERRORS or COUNT_HANDSHAKE_ERRORS instead, but, if specified or the error is unknown, this column is incremented.',"
+                      "COUNT_HANDSHAKE_ERRORS BIGINT not null comment 'Number of errors detected at the wire protocol level.',"
+                      "COUNT_PROXY_USER_ERRORS BIGINT not null comment 'Number of errors detected when a proxy user is proxied to a user that does not exist.',"
+                      "COUNT_PROXY_USER_ACL_ERRORS BIGINT not null comment 'Number of errors detected when a proxy user is proxied to a user that exists, but the proxy user doesn''t have the PROXY privilege.',"
+                      "COUNT_AUTHENTICATION_ERRORS BIGINT not null comment 'Number of errors where authentication failed.',"
+                      "COUNT_SSL_ERRORS BIGINT not null comment 'Number of errors due to TLS problems.',"
+                      "COUNT_MAX_USER_CONNECTIONS_ERRORS BIGINT not null comment 'Number of errors due to the per-user quota being exceeded.',"
+                      "COUNT_MAX_USER_CONNECTIONS_PER_HOUR_ERRORS BIGINT not null comment 'Number of errors due to the per-hour quota being exceeded.',"
+                      "COUNT_DEFAULT_DATABASE_ERRORS BIGINT not null comment 'Number of errors due to the user not having permission to access the specified default database, or it not existing.',"
+                      "COUNT_INIT_CONNECT_ERRORS BIGINT not null comment 'Number of errors due to statements in the init_connect system variable.',"
+                      "COUNT_LOCAL_ERRORS BIGINT not null comment 'Number of local server errors, such as out-of-memory errors, unrelated to network, authentication, or authorization.',"
+                      "COUNT_UNKNOWN_ERRORS BIGINT not null comment 'Number of unknown errors that cannot be allocated to another column.',"
+                      "FIRST_SEEN TIMESTAMP(0) NOT NULL default 0 comment 'Timestamp of the first connection attempt by the IP.',"
+                      "LAST_SEEN TIMESTAMP(0) NOT NULL default 0 comment 'Timestamp of the most recent connection attempt by the IP.',"
+                      "FIRST_ERROR_SEEN TIMESTAMP(0) null default 0 comment 'Timestamp of the first error seen from the IP.',"
+                      "LAST_ERROR_SEEN TIMESTAMP(0) null default 0 comment 'Timestamp of the most recent error seen from the IP.')") }
 };
 
 PFS_engine_table* table_host_cache::create(void)

storage/perfschema/table_hosts.cc

@@ -44,9 +44,9 @@ table_hosts::m_share=
   sizeof(PFS_simple_index), /* ref length */
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE hosts("
-                      "HOST CHAR(" STRINGIFY_ARG(HOSTNAME_LENGTH) ") collate utf8_bin default null,"
-                      "CURRENT_CONNECTIONS bigint not null,"
-                      "TOTAL_CONNECTIONS bigint not null)") }
+                      "HOST CHAR(" STRINGIFY_ARG(HOSTNAME_LENGTH) ") collate utf8_bin default null comment 'Host name used by the client to connect, NULL for internal threads or user sessions that failed to authenticate.',"
+                      "CURRENT_CONNECTIONS bigint not null comment 'Current number of the host''s connections.',"
+                      "TOTAL_CONNECTIONS bigint not null comment 'Total number of the host''s connections')") }
 };
 
 PFS_engine_table* table_hosts::create()

storage/perfschema/table_os_global_by_type.cc

@@ -48,14 +48,14 @@ table_os_global_by_type::m_share=
   sizeof(pos_os_global_by_type),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE objects_summary_global_by_type("
-                      "OBJECT_TYPE VARCHAR(64),"
-                      "OBJECT_SCHEMA VARCHAR(64),"
-                      "OBJECT_NAME VARCHAR(64),"
-                      "COUNT_STAR BIGINT unsigned not null,"
-                      "SUM_TIMER_WAIT BIGINT unsigned not null,"
-                      "MIN_TIMER_WAIT BIGINT unsigned not null,"
-                      "AVG_TIMER_WAIT BIGINT unsigned not null,"
-                      "MAX_TIMER_WAIT BIGINT unsigned not null)") }
+                      "OBJECT_TYPE VARCHAR(64) comment 'Groups records together with OBJECT_SCHEMA and OBJECT_NAME.',"
+                      "OBJECT_SCHEMA VARCHAR(64) comment 'Groups records together with OBJECT_TYPE and OBJECT_NAME.',"
+                      "OBJECT_NAME VARCHAR(64) comment 'Groups records together with OBJECT_SCHEMA and OBJECT_TYPE.',"
+                      "COUNT_STAR BIGINT unsigned not null comment 'Number of summarized events',"
+                      "SUM_TIMER_WAIT BIGINT unsigned not null comment 'Total wait time of the summarized events that are timed.',"
+                      "MIN_TIMER_WAIT BIGINT unsigned not null comment 'Minimum wait time of the summarized events that are timed.',"
+                      "AVG_TIMER_WAIT BIGINT unsigned not null comment 'Average wait time of the summarized events that are timed.',"
+                      "MAX_TIMER_WAIT BIGINT unsigned not null comment 'Maximum wait time of the summarized events that are timed.')") }
 };
 
 PFS_engine_table*

storage/perfschema/table_performance_timers.cc

@@ -46,10 +46,10 @@ table_performance_timers::m_share=
   sizeof(PFS_simple_index), /* ref length */
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE performance_timers("
-                      "TIMER_NAME ENUM ('CYCLE', 'NANOSECOND', 'MICROSECOND', 'MILLISECOND', 'TICK') not null,"
-                      "TIMER_FREQUENCY BIGINT,"
-                      "TIMER_RESOLUTION BIGINT,"
-                      "TIMER_OVERHEAD BIGINT)") }
+                      "TIMER_NAME ENUM ('CYCLE', 'NANOSECOND', 'MICROSECOND', 'MILLISECOND', 'TICK') not null comment 'Time name, used in the setup_timers table.',"
+                      "TIMER_FREQUENCY BIGINT comment 'Number of timer units per second. Dependent on the processor speed.',"
+                      "TIMER_RESOLUTION BIGINT comment 'Number of timer units by which timed values increase each time.',"
+                      "TIMER_OVERHEAD BIGINT comment 'Minimum timer overhead, determined during initialization by calling the timer 20 times and selecting the smallest value. Total overhead will be at least double this, as the timer is called at the beginning and end of each timed event.')") }
 };
 
 PFS_engine_table* table_performance_timers::create(void)

storage/perfschema/table_session_account_connect_attrs.cc

@@ -37,10 +37,10 @@ table_session_account_connect_attrs::m_share=
   sizeof(pos_connect_attr_by_thread_by_attr), /* ref length */
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE session_account_connect_attrs("
-                      "PROCESSLIST_ID INT NOT NULL,"
-                      "ATTR_NAME VARCHAR(32) NOT NULL,"
-                      "ATTR_VALUE VARCHAR(1024),"
-                      "ORDINAL_POSITION INT"
+                      "PROCESSLIST_ID INT NOT NULL comment 'Session connection identifier.',"
+                      "ATTR_NAME VARCHAR(32) NOT NULL comment 'Attribute name.',"
+                      "ATTR_VALUE VARCHAR(1024) comment 'Attribute value.',"
+                      "ORDINAL_POSITION INT comment 'Order in which attribute was added to the connection attributes.'"
                       ") CHARACTER SET utf8 COLLATE utf8_bin") }
 };
 

storage/perfschema/table_session_connect_attrs.cc

@@ -37,10 +37,10 @@ table_session_connect_attrs::m_share=
   sizeof(pos_connect_attr_by_thread_by_attr), /* ref length */
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE session_connect_attrs("
-                      "PROCESSLIST_ID INT NOT NULL,"
-                      "ATTR_NAME VARCHAR(32) NOT NULL,"
-                      "ATTR_VALUE VARCHAR(1024),"
-                      "ORDINAL_POSITION INT"
+                      "PROCESSLIST_ID INT NOT NULL comment 'Session connection identifier.',"
+                      "ATTR_NAME VARCHAR(32) NOT NULL comment 'Attribute name.',"
+                      "ATTR_VALUE VARCHAR(1024) comment 'Attribute value.',"
+                      "ORDINAL_POSITION INT comment 'Order in which attribute was added to the connection attributes.'"
                       ") CHARACTER SET utf8 COLLATE utf8_bin") }
 };
 

storage/perfschema/table_setup_actors.cc

@@ -49,9 +49,9 @@ table_setup_actors::m_share=
   sizeof(PFS_simple_index),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE setup_actors("
-                      "HOST CHAR(" STRINGIFY_ARG(HOSTNAME_LENGTH) ") collate utf8_bin default '%' not null,"
-                      "USER CHAR(" STRINGIFY_ARG(USERNAME_CHAR_LENGTH) ") collate utf8_bin default '%' not null,"
-                      "ROLE CHAR(" STRINGIFY_ARG(USERNAME_CHAR_LENGTH) ") collate utf8_bin default '%' not null)") }
+                      "HOST CHAR(" STRINGIFY_ARG(HOSTNAME_LENGTH) ") collate utf8_bin default '%' not null comment 'Host name, either a literal, or the % wildcard representing any host.',"
+                      "USER CHAR(" STRINGIFY_ARG(USERNAME_CHAR_LENGTH) ") collate utf8_bin default '%' not null comment 'User name, either a literal or the % wildcard representing any name.',"
+                      "ROLE CHAR(" STRINGIFY_ARG(USERNAME_CHAR_LENGTH) ") collate utf8_bin default '%' not null comment 'Unused')") }
 };
 
 PFS_engine_table* table_setup_actors::create()

storage/perfschema/table_setup_consumers.cc

@@ -112,8 +112,8 @@ table_setup_consumers::m_share=
   sizeof(PFS_simple_index), /* ref length */
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE setup_consumers("
-                      "NAME VARCHAR(64) not null,"
-                      "ENABLED ENUM ('YES', 'NO') not null)") }
+                      "NAME VARCHAR(64) not null comment 'Consumer name',"
+                      "ENABLED ENUM ('YES', 'NO') not null comment 'YES or NO for whether or not the consumer is enabled. You can modify this column to ensure that event information is added, or is not added.')") }
 };
 
 PFS_engine_table* table_setup_consumers::create(void)

storage/perfschema/table_setup_instruments.cc

@@ -50,9 +50,9 @@ table_setup_instruments::m_share=
   sizeof(pos_setup_instruments),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE setup_instruments("
-                      "NAME VARCHAR(128) not null,"
-                      "ENABLED ENUM ('YES', 'NO') not null,"
-                      "TIMED ENUM ('YES', 'NO') not null)") }
+                      "NAME VARCHAR(128) not null comment 'Instrument name',"
+                      "ENABLED ENUM ('YES', 'NO') not null comment 'Whether or not the instrument is enabled. It can be disabled, and the instrument will produce no events.',"
+                      "TIMED ENUM ('YES', 'NO') not null comment 'Whether or not the instrument is timed. It can be set, but if disabled, events produced by the instrument will have NULL values for the corresponding TIMER_START, TIMER_END, and TIMER_WAIT values.')") }
 };
 
 PFS_engine_table* table_setup_instruments::create(void)

storage/perfschema/table_setup_objects.cc

@@ -50,11 +50,11 @@ table_setup_objects::m_share=
   sizeof(PFS_simple_index),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE setup_objects("
-                      "OBJECT_TYPE ENUM ('TABLE') not null default 'TABLE',"
-                      "OBJECT_SCHEMA VARCHAR(64) default '%',"
-                      "OBJECT_NAME VARCHAR(64) not null default '%',"
-                      "ENABLED ENUM ('YES', 'NO') not null default 'YES',"
-                      "TIMED ENUM ('YES', 'NO') not null default 'YES')") }
+                      "OBJECT_TYPE ENUM ('TABLE') not null default 'TABLE' comment 'Type of object to instrument. Currently, only TABLE, for base table.',"
+                      "OBJECT_SCHEMA VARCHAR(64) default '%' comment 'Schema containing the object, either the literal or % for any schema.',"
+                      "OBJECT_NAME VARCHAR(64) not null default '%' comment 'Name of the instrumented object, either the literal or % for any object.',"
+                      "ENABLED ENUM ('YES', 'NO') not null default 'YES' comment 'Whether the object''s events are instrumented or not. Can be disabled, in which case monitoring is not enabled for those objects.',"
+                      "TIMED ENUM ('YES', 'NO') not null default 'YES' comment 'Whether the object''s events are timed or not. Can be modified.')") }
 };
 
 int update_derived_flags()

storage/perfschema/table_setup_timers.cc

@@ -68,8 +68,8 @@ table_setup_timers::m_share=
   sizeof(PFS_simple_index),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE setup_timers("
-                      "NAME VARCHAR(64) not null,"
-                      "TIMER_NAME ENUM ('CYCLE', 'NANOSECOND', 'MICROSECOND', 'MILLISECOND', 'TICK') not null)") }
+                      "NAME VARCHAR(64) not null comment 'Type of instrument the timer is used for.',"
+                      "TIMER_NAME ENUM ('CYCLE', 'NANOSECOND', 'MICROSECOND', 'MILLISECOND', 'TICK') not null comment 'Timer applying to the instrument type. Can be modified.')") }
 };
 
 PFS_engine_table* table_setup_timers::create(void)

storage/perfschema/table_socket_instances.cc

@@ -48,13 +48,13 @@ table_socket_instances::m_share=
   sizeof(PFS_simple_index),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE socket_instances("
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned not null,"
-                      "THREAD_ID BIGINT unsigned,"
-                      "SOCKET_ID INTEGER not null,"
-                      "IP VARCHAR(64) not null,"
-                      "PORT INTEGER not null,"
-                      "STATE ENUM('IDLE','ACTIVE') not null)") }
+                      "EVENT_NAME VARCHAR(128) not null comment 'NAME from the setup_instruments table, and the name of the wait/io/socket/* instrument that produced the event.',"
+                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned not null comment 'Memory address of the object.',"
+                      "THREAD_ID BIGINT unsigned comment 'Thread identifier that the server assigns to each socket.',"
+                      "SOCKET_ID INTEGER not null comment 'The socket''s internal file handle.',"
+                      "IP VARCHAR(64) not null comment 'Client IP address. Blank for Unix socket file, otherwise an IPv4 or IPv6 address. Together with the PORT identifies the connection.',"
+                      "PORT INTEGER not null comment 'TCP/IP port number, from 0 to 65535. Together with the IP identifies the connection.',"
+                      "STATE ENUM('IDLE','ACTIVE') not null comment 'Socket status, either IDLE if waiting to receive a request from a client, or ACTIVE')") }
 };
 
 PFS_engine_table* table_socket_instances::create(void)

storage/perfschema/table_socket_summary_by_event_name.cc

@@ -49,29 +49,29 @@ table_socket_summary_by_event_name::m_share=
   sizeof(PFS_simple_index),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE socket_summary_by_event_name("
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "COUNT_STAR BIGINT unsigned not null,"
-                      "SUM_TIMER_WAIT BIGINT unsigned not null,"
-                      "MIN_TIMER_WAIT BIGINT unsigned not null,"
-                      "AVG_TIMER_WAIT BIGINT unsigned not null,"
-                      "MAX_TIMER_WAIT BIGINT unsigned not null,"
-                      "COUNT_READ BIGINT unsigned not null,"
-                      "SUM_TIMER_READ BIGINT unsigned not null,"
-                      "MIN_TIMER_READ BIGINT unsigned not null,"
-                      "AVG_TIMER_READ BIGINT unsigned not null,"
-                      "MAX_TIMER_READ BIGINT unsigned not null,"
-                      "SUM_NUMBER_OF_BYTES_READ BIGINT unsigned not null,"
-                      "COUNT_WRITE BIGINT unsigned not null,"
-                      "SUM_TIMER_WRITE BIGINT unsigned not null,"
-                      "MIN_TIMER_WRITE BIGINT unsigned not null,"
-                      "AVG_TIMER_WRITE BIGINT unsigned not null,"
-                      "MAX_TIMER_WRITE BIGINT unsigned not null,"
-                      "SUM_NUMBER_OF_BYTES_WRITE BIGINT unsigned not null,"
-                      "COUNT_MISC BIGINT unsigned not null,"
-                      "SUM_TIMER_MISC BIGINT unsigned not null,"
-                      "MIN_TIMER_MISC BIGINT unsigned not null,"
-                      "AVG_TIMER_MISC BIGINT unsigned not null,"
-                      "MAX_TIMER_MISC BIGINT unsigned not null)") }
+                      "EVENT_NAME VARCHAR(128) not null comment 'Socket instrument.',"
+                      "COUNT_STAR BIGINT unsigned not null comment 'Number of summarized events',"
+                      "SUM_TIMER_WAIT BIGINT unsigned not null comment 'Total wait time of the summarized events that are timed.',"
+                      "MIN_TIMER_WAIT BIGINT unsigned not null comment 'Minimum wait time of the summarized events that are timed.',"
+                      "AVG_TIMER_WAIT BIGINT unsigned not null comment 'Average wait time of the summarized events that are timed.',"
+                      "MAX_TIMER_WAIT BIGINT unsigned not null comment 'Maximum wait time of the summarized events that are timed.',"
+                      "COUNT_READ BIGINT unsigned not null comment 'Number of all read operations, including RECV, RECVFROM, and RECVMSG.',"
+                      "SUM_TIMER_READ BIGINT unsigned not null comment 'Total wait time of all read operations that are timed.',"
+                      "MIN_TIMER_READ BIGINT unsigned not null comment 'Minimum wait time of all read operations that are timed.',"
+                      "AVG_TIMER_READ BIGINT unsigned not null comment 'Average wait time of all read operations that are timed.',"
+                      "MAX_TIMER_READ BIGINT unsigned not null comment 'Maximum wait time of all read operations that are timed.',"
+                      "SUM_NUMBER_OF_BYTES_READ BIGINT unsigned not null comment 'Bytes read by read operations.',"
+                      "COUNT_WRITE BIGINT unsigned not null comment 'Number of all write operations, including SEND, SENDTO, and SENDMSG.',"
+                      "SUM_TIMER_WRITE BIGINT unsigned not null comment 'Total wait time of all write operations that are timed.',"
+                      "MIN_TIMER_WRITE BIGINT unsigned not null comment 'Minimum wait time of all write operations that are timed.',"
+                      "AVG_TIMER_WRITE BIGINT unsigned not null comment 'Average wait time of all write operations that are timed.',"
+                      "MAX_TIMER_WRITE BIGINT unsigned not null comment 'Maximum wait time of all write operations that are timed.',"
+                      "SUM_NUMBER_OF_BYTES_WRITE BIGINT unsigned not null comment 'Bytes written by write operations.',"
+                      "COUNT_MISC BIGINT unsigned not null comment 'Number of all miscellaneous operations not counted above, including CONNECT, LISTEN, ACCEPT, CLOSE, and SHUTDOWN.',"
+                      "SUM_TIMER_MISC BIGINT unsigned not null comment 'Total wait time of all miscellaneous operations that are timed.',"
+                      "MIN_TIMER_MISC BIGINT unsigned not null comment 'Minimum wait time of all miscellaneous operations that are timed.',"
+                      "AVG_TIMER_MISC BIGINT unsigned not null comment 'Average wait time of all miscellaneous operations that are timed.',"
+                      "MAX_TIMER_MISC BIGINT unsigned not null comment 'Maximum wait time of all miscellaneous operations that are timed.')") }
 };
 
 PFS_engine_table* table_socket_summary_by_event_name::create(void)

storage/perfschema/table_socket_summary_by_instance.cc

@@ -48,30 +48,30 @@ table_socket_summary_by_instance::m_share=
   sizeof(PFS_simple_index),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE socket_summary_by_instance("
-                      "EVENT_NAME VARCHAR(128) not null,"
-                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned not null,"
-                      "COUNT_STAR BIGINT unsigned not null,"
-                      "SUM_TIMER_WAIT BIGINT unsigned not null,"
-                      "MIN_TIMER_WAIT BIGINT unsigned not null,"
-                      "AVG_TIMER_WAIT BIGINT unsigned not null,"
-                      "MAX_TIMER_WAIT BIGINT unsigned not null,"
-                      "COUNT_READ BIGINT unsigned not null,"
-                      "SUM_TIMER_READ BIGINT unsigned not null,"
-                      "MIN_TIMER_READ BIGINT unsigned not null,"
-                      "AVG_TIMER_READ BIGINT unsigned not null,"
-                      "MAX_TIMER_READ BIGINT unsigned not null,"
-                      "SUM_NUMBER_OF_BYTES_READ BIGINT unsigned not null,"
-                      "COUNT_WRITE BIGINT unsigned not null,"
-                      "SUM_TIMER_WRITE BIGINT unsigned not null,"
-                      "MIN_TIMER_WRITE BIGINT unsigned not null,"
-                      "AVG_TIMER_WRITE BIGINT unsigned not null,"
-                      "MAX_TIMER_WRITE BIGINT unsigned not null,"
-                      "SUM_NUMBER_OF_BYTES_WRITE BIGINT unsigned not null,"
-                      "COUNT_MISC BIGINT unsigned not null,"
-                      "SUM_TIMER_MISC BIGINT unsigned not null,"
-                      "MIN_TIMER_MISC BIGINT unsigned not null,"
-                      "AVG_TIMER_MISC BIGINT unsigned not null,"
-                      "MAX_TIMER_MISC BIGINT unsigned not null)") }
+                      "EVENT_NAME VARCHAR(128) not null comment 'Socket instrument.',"
+                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned not null comment 'Address in memory.',"
+                      "COUNT_STAR BIGINT unsigned not null comment 'Number of summarized events',"
+                      "SUM_TIMER_WAIT BIGINT unsigned not null comment 'Total wait time of the summarized events that are timed.',"
+                      "MIN_TIMER_WAIT BIGINT unsigned not null comment 'Minimum wait time of the summarized events that are timed.',"
+                      "AVG_TIMER_WAIT BIGINT unsigned not null comment 'Average wait time of the summarized events that are timed.',"
+                      "MAX_TIMER_WAIT BIGINT unsigned not null comment 'Maximum wait time of the summarized events that are timed.',"
+                      "COUNT_READ BIGINT unsigned not null comment 'Number of all read operations, including RECV, RECVFROM, and RECVMSG.',"
+                      "SUM_TIMER_READ BIGINT unsigned not null comment 'Total wait time of all read operations that are timed.',"
+                      "MIN_TIMER_READ BIGINT unsigned not null comment 'Minimum wait time of all read operations that are timed.',"
+                      "AVG_TIMER_READ BIGINT unsigned not null comment 'Average wait time of all read operations that are timed.',"
+                      "MAX_TIMER_READ BIGINT unsigned not null comment 'Maximum wait time of all read operations that are timed.',"
+                      "SUM_NUMBER_OF_BYTES_READ BIGINT unsigned not null comment 'Bytes read by read operations.',"
+                      "COUNT_WRITE BIGINT unsigned not null comment 'Number of all write operations, including SEND, SENDTO, and SENDMSG.',"
+                      "SUM_TIMER_WRITE BIGINT unsigned not null comment 'Total wait time of all write operations that are timed.',"
+                      "MIN_TIMER_WRITE BIGINT unsigned not null comment 'Minimum wait time of all write operations that are timed.',"
+                      "AVG_TIMER_WRITE BIGINT unsigned not null comment 'Average wait time of all write operations that are timed.',"
+                      "MAX_TIMER_WRITE BIGINT unsigned not null comment 'Maximum wait time of all write operations that are timed.',"
+                      "SUM_NUMBER_OF_BYTES_WRITE BIGINT unsigned not null comment 'Bytes written by write operations.',"
+                      "COUNT_MISC BIGINT unsigned not null comment 'Number of all miscellaneous operations not counted above, including CONNECT, LISTEN, ACCEPT, CLOSE, and SHUTDOWN.',"
+                      "SUM_TIMER_MISC BIGINT unsigned not null comment 'Total wait time of all miscellaneous operations that are timed.',"
+                      "MIN_TIMER_MISC BIGINT unsigned not null comment 'Minimum wait time of all miscellaneous operations that are timed.',"
+                      "AVG_TIMER_MISC BIGINT unsigned not null comment 'Average wait time of all miscellaneous operations that are timed.',"
+                      "MAX_TIMER_MISC BIGINT unsigned not null comment 'Maximum wait time of all miscellaneous operations that are timed.')") }
 };
 
 PFS_engine_table* table_socket_summary_by_instance::create(void)

storage/perfschema/table_sync_instances.cc

@@ -49,9 +49,9 @@ table_mutex_instances::m_share=
   sizeof(PFS_simple_index),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE mutex_instances("
-                      "NAME VARCHAR(128) not null,"
-                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned not null,"
-                      "LOCKED_BY_THREAD_ID BIGINT unsigned)") }
+                      "NAME VARCHAR(128) not null comment 'Instrument name associated with the mutex.',"
+                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned not null comment 'Memory address of the instrumented mutex.',"
+                      "LOCKED_BY_THREAD_ID BIGINT unsigned comment 'The THREAD_ID of the locking thread if a thread has a mutex locked, otherwise NULL.')") }
 };
 
 PFS_engine_table* table_mutex_instances::create(void)
@@ -192,10 +192,10 @@ table_rwlock_instances::m_share=
   sizeof(PFS_simple_index),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE rwlock_instances("
-                      "NAME VARCHAR(128) not null,"
-                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned not null,"
-                      "WRITE_LOCKED_BY_THREAD_ID BIGINT unsigned,"
-                      "READ_LOCKED_BY_COUNT INTEGER unsigned not null)") }
+                      "NAME VARCHAR(128) not null comment 'Instrument name associated with the read write lock',"
+                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned not null comment 'Address in memory of the instrumented lock',"
+                      "WRITE_LOCKED_BY_THREAD_ID BIGINT unsigned comment 'THREAD_ID of the locking thread if locked in write (exclusive) mode, otherwise NULL.',"
+                      "READ_LOCKED_BY_COUNT INTEGER unsigned not null comment 'Count of current read locks held')") }
 };
 
 PFS_engine_table* table_rwlock_instances::create(void)
@@ -343,8 +343,8 @@ table_cond_instances::m_share=
   sizeof(PFS_simple_index),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE cond_instances("
-                      "NAME VARCHAR(128) not null,"
-                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned not null)") }
+                      "NAME VARCHAR(128) not null comment 'Client user name for the connection, or NULL if an internal thread.',"
+                      "OBJECT_INSTANCE_BEGIN BIGINT unsigned not null comment 'Address in memory of the instrumented condition.')") }
 };
 
 PFS_engine_table* table_cond_instances::create(void)

storage/perfschema/table_threads.cc

@@ -42,20 +42,20 @@ table_threads::m_share=
   sizeof(PFS_simple_index), /* ref length */
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE threads("
-                      "THREAD_ID BIGINT unsigned not null,"
-                      "NAME VARCHAR(128) not null,"
-                      "TYPE VARCHAR(10) not null,"
-                      "PROCESSLIST_ID BIGINT unsigned,"
-                      "PROCESSLIST_USER VARCHAR(" STRINGIFY_ARG(USERNAME_CHAR_LENGTH) "),"
-                      "PROCESSLIST_HOST VARCHAR(" STRINGIFY_ARG(HOSTNAME_LENGTH) "),"
-                      "PROCESSLIST_DB VARCHAR(64),"
-                      "PROCESSLIST_COMMAND VARCHAR(16),"
-                      "PROCESSLIST_TIME BIGINT,"
-                      "PROCESSLIST_STATE VARCHAR(64),"
-                      "PROCESSLIST_INFO LONGTEXT,"
-                      "PARENT_THREAD_ID BIGINT unsigned,"
-                      "ROLE VARCHAR(64),"
-                      "INSTRUMENTED ENUM ('YES', 'NO') not null)") }
+                      "THREAD_ID BIGINT unsigned not null comment 'A unique thread identifier.',"
+                      "NAME VARCHAR(128) not null comment 'Name associated with the server''s thread instrumentation code, for example thread/sql/main for the server''s main() function, and thread/sql/one_connection for a user connection.',"
+                      "TYPE VARCHAR(10) not null comment 'FOREGROUND or BACKGROUND, depending on the thread type. User connection threads are FOREGROUND, internal server threads are BACKGROUND.',"
+                      "PROCESSLIST_ID BIGINT unsigned comment 'The PROCESSLIST.ID value for threads displayed in the INFORMATION_SCHEMA.PROCESSLIST table, or 0 for background threads. Also corresponds with the CONNECTION_ID() return value for the thread.',"
+                      "PROCESSLIST_USER VARCHAR(" STRINGIFY_ARG(USERNAME_CHAR_LENGTH) ") comment 'Foreground thread user, or NULL for a background thread.',"
+                      "PROCESSLIST_HOST VARCHAR(" STRINGIFY_ARG(HOSTNAME_LENGTH) ") comment 'Foreground thread host, or NULL for a background thread.',"
+                      "PROCESSLIST_DB VARCHAR(64) comment 'Thread''s default database, or NULL if none exists.',"
+                      "PROCESSLIST_COMMAND VARCHAR(16) comment 'Type of command executed by the thread. These correspond to the the COM_xxx client/server protocol commands, and the Com_xxx status variables. See Thread Command Values.',"
+                      "PROCESSLIST_TIME BIGINT comment 'Time in seconds the thread has been in its current state.',"
+                      "PROCESSLIST_STATE VARCHAR(64) comment 'Action, event or state indicating what the thread is doing.',"
+                      "PROCESSLIST_INFO LONGTEXT comment 'Statement being executed by the thread, or NULL if a statement is not being executed. If a statement results in calling other statements, such as for a stored procedure, the innermost statement from the stored procedure is shown here.',"
+                      "PARENT_THREAD_ID BIGINT unsigned comment 'THREAD_ID of the parent thread, if any. Subthreads can for example be spawned as a result of INSERT DELAYED statements.',"
+                      "ROLE VARCHAR(64) comment 'Unused.',"
+                      "INSTRUMENTED ENUM ('YES', 'NO') not null comment 'YES or NO for Whether the thread is instrumented or not. For foreground threads, the initial value is determined by whether there''s a user/host match in the setup_actors table. Subthreads are again matched, while for background threads, this will be set to YES by default. To monitor events that the thread executes, INSTRUMENTED must be YES and the thread_instrumentation consumer in the setup_consumers table must also be YES.')") }
 };
 
 PFS_engine_table* table_threads::create()

storage/perfschema/table_tiws_by_index_usage.cc

@@ -49,45 +49,45 @@ table_tiws_by_index_usage::m_share=
   sizeof(pos_tiws_by_index_usage),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE table_io_waits_summary_by_index_usage("
-                      "OBJECT_TYPE VARCHAR(64),"
-                      "OBJECT_SCHEMA VARCHAR(64),"
-                      "OBJECT_NAME VARCHAR(64),"
-                      "INDEX_NAME VARCHAR(64),"
-                      "COUNT_STAR BIGINT unsigned not null,"
-                      "SUM_TIMER_WAIT BIGINT unsigned not null,"
-                      "MIN_TIMER_WAIT BIGINT unsigned not null,"
-                      "AVG_TIMER_WAIT BIGINT unsigned not null,"
-                      "MAX_TIMER_WAIT BIGINT unsigned not null,"
-                      "COUNT_READ BIGINT unsigned not null,"
-                      "SUM_TIMER_READ BIGINT unsigned not null,"
-                      "MIN_TIMER_READ BIGINT unsigned not null,"
-                      "AVG_TIMER_READ BIGINT unsigned not null,"
-                      "MAX_TIMER_READ BIGINT unsigned not null,"
-                      "COUNT_WRITE BIGINT unsigned not null,"
-                      "SUM_TIMER_WRITE BIGINT unsigned not null,"
-                      "MIN_TIMER_WRITE BIGINT unsigned not null,"
-                      "AVG_TIMER_WRITE BIGINT unsigned not null,"
-                      "MAX_TIMER_WRITE BIGINT unsigned not null,"
-                      "COUNT_FETCH BIGINT unsigned not null,"
-                      "SUM_TIMER_FETCH BIGINT unsigned not null,"
-                      "MIN_TIMER_FETCH BIGINT unsigned not null,"
-                      "AVG_TIMER_FETCH BIGINT unsigned not null,"
-                      "MAX_TIMER_FETCH BIGINT unsigned not null,"
-                      "COUNT_INSERT BIGINT unsigned not null,"
-                      "SUM_TIMER_INSERT BIGINT unsigned not null,"
-                      "MIN_TIMER_INSERT BIGINT unsigned not null,"
-                      "AVG_TIMER_INSERT BIGINT unsigned not null,"
-                      "MAX_TIMER_INSERT BIGINT unsigned not null,"
-                      "COUNT_UPDATE BIGINT unsigned not null,"
-                      "SUM_TIMER_UPDATE BIGINT unsigned not null,"
-                      "MIN_TIMER_UPDATE BIGINT unsigned not null,"
-                      "AVG_TIMER_UPDATE BIGINT unsigned not null,"
-                      "MAX_TIMER_UPDATE BIGINT unsigned not null,"
-                      "COUNT_DELETE BIGINT unsigned not null,"
-                      "SUM_TIMER_DELETE BIGINT unsigned not null,"
-                      "MIN_TIMER_DELETE BIGINT unsigned not null,"
-                      "AVG_TIMER_DELETE BIGINT unsigned not null,"
-                      "MAX_TIMER_DELETE BIGINT unsigned not null)") }
+                      "OBJECT_TYPE VARCHAR(64) comment 'TABLE in the case of all indexes.',"
+                      "OBJECT_SCHEMA VARCHAR(64) comment 'Schema name.',"
+                      "OBJECT_NAME VARCHAR(64) comment 'Table name.',"
+                      "INDEX_NAME VARCHAR(64) comment 'Index name, or PRIMARY for the primary index, NULL for no index (inserts are counted in this case).',"
+                      "COUNT_STAR BIGINT unsigned not null comment 'Number of summarized events and the sum of the x_READ and x_WRITE columns.',"
+                      "SUM_TIMER_WAIT BIGINT unsigned not null comment 'Total wait time of the summarized events that are timed.',"
+                      "MIN_TIMER_WAIT BIGINT unsigned not null comment 'Minimum wait time of the summarized events that are timed.',"
+                      "AVG_TIMER_WAIT BIGINT unsigned not null comment 'Average wait time of the summarized events that are timed.',"
+                      "MAX_TIMER_WAIT BIGINT unsigned not null comment 'Maximum wait time of the summarized events that are timed.',"
+                      "COUNT_READ BIGINT unsigned not null comment 'Number of all read operations, and the sum of the equivalent x_FETCH columns.',"
+                      "SUM_TIMER_READ BIGINT unsigned not null comment 'Total wait time of all read operations that are timed.',"
+                      "MIN_TIMER_READ BIGINT unsigned not null comment 'Minimum wait time of all read operations that are timed.',"
+                      "AVG_TIMER_READ BIGINT unsigned not null comment 'Average wait time of all read operations that are timed.',"
+                      "MAX_TIMER_READ BIGINT unsigned not null comment 'Maximum wait time of all read operations that are timed.',"
+                      "COUNT_WRITE BIGINT unsigned not null comment 'Number of all write operations, and the sum of the equivalent x_INSERT, x_UPDATE and x_DELETE columns.',"
+                      "SUM_TIMER_WRITE BIGINT unsigned not null comment 'Total wait time of all write operations that are timed.',"
+                      "MIN_TIMER_WRITE BIGINT unsigned not null comment 'Minimum wait time of all write operations that are timed.',"
+                      "AVG_TIMER_WRITE BIGINT unsigned not null comment 'Average wait time of all write operations that are timed.',"
+                      "MAX_TIMER_WRITE BIGINT unsigned not null comment 'Maximum wait time of all write operations that are timed.',"
+                      "COUNT_FETCH BIGINT unsigned not null comment 'Number of all fetch operations.',"
+                      "SUM_TIMER_FETCH BIGINT unsigned not null comment 'Total wait time of all fetch operations that are timed.',"
+                      "MIN_TIMER_FETCH BIGINT unsigned not null comment 'Minimum wait time of all fetch operations that are timed.',"
+                      "AVG_TIMER_FETCH BIGINT unsigned not null comment 'Average wait time of all fetch operations that are timed.',"
+                      "MAX_TIMER_FETCH BIGINT unsigned not null comment 'Maximum wait time of all fetch operations that are timed.',"
+                      "COUNT_INSERT BIGINT unsigned not null comment 'Number of all insert operations.',"
+                      "SUM_TIMER_INSERT BIGINT unsigned not null comment 'Total wait time of all insert operations that are timed.',"
+                      "MIN_TIMER_INSERT BIGINT unsigned not null comment 'Minimum wait time of all insert operations that are timed.',"
+                      "AVG_TIMER_INSERT BIGINT unsigned not null comment 'Average wait time of all insert operations that are timed.',"
+                      "MAX_TIMER_INSERT BIGINT unsigned not null comment 'Maximum wait time of all insert operations that are timed.',"
+                      "COUNT_UPDATE BIGINT unsigned not null comment 'Number of all update operations.',"
+                      "SUM_TIMER_UPDATE BIGINT unsigned not null comment 'Total wait time of all update operations that are timed.',"
+                      "MIN_TIMER_UPDATE BIGINT unsigned not null comment 'Minimum wait time of all update operations that are timed.',"
+                      "AVG_TIMER_UPDATE BIGINT unsigned not null comment 'Average wait time of all update operations that are timed.',"
+                      "MAX_TIMER_UPDATE BIGINT unsigned not null comment 'Maximum wait time of all update operations that are timed.',"
+                      "COUNT_DELETE BIGINT unsigned not null comment 'Number of all delete operations.',"
+                      "SUM_TIMER_DELETE BIGINT unsigned not null comment 'Total wait time of all delete operations that are timed.',"
+                      "MIN_TIMER_DELETE BIGINT unsigned not null comment 'Minimum wait time of all delete operations that are timed.',"
+                      "AVG_TIMER_DELETE BIGINT unsigned not null comment 'Average wait time of all delete operations that are timed.',"
+                      "MAX_TIMER_DELETE BIGINT unsigned not null comment 'Maximum wait time of all delete operations that are timed.')") }
 };
 
 PFS_engine_table*

storage/perfschema/table_tiws_by_table.cc

@@ -49,44 +49,44 @@ table_tiws_by_table::m_share=
   sizeof(PFS_simple_index),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE table_io_waits_summary_by_table("
-                      "OBJECT_TYPE VARCHAR(64),"
-                      "OBJECT_SCHEMA VARCHAR(64),"
-                      "OBJECT_NAME VARCHAR(64),"
-                      "COUNT_STAR BIGINT unsigned not null,"
-                      "SUM_TIMER_WAIT BIGINT unsigned not null,"
-                      "MIN_TIMER_WAIT BIGINT unsigned not null,"
-                      "AVG_TIMER_WAIT BIGINT unsigned not null,"
-                      "MAX_TIMER_WAIT BIGINT unsigned not null,"
-                      "COUNT_READ BIGINT unsigned not null,"
-                      "SUM_TIMER_READ BIGINT unsigned not null,"
-                      "MIN_TIMER_READ BIGINT unsigned not null,"
-                      "AVG_TIMER_READ BIGINT unsigned not null,"
-                      "MAX_TIMER_READ BIGINT unsigned not null,"
-                      "COUNT_WRITE BIGINT unsigned not null,"
-                      "SUM_TIMER_WRITE BIGINT unsigned not null,"
-                      "MIN_TIMER_WRITE BIGINT unsigned not null,"
-                      "AVG_TIMER_WRITE BIGINT unsigned not null,"
-                      "MAX_TIMER_WRITE BIGINT unsigned not null,"
-                      "COUNT_FETCH BIGINT unsigned not null,"
-                      "SUM_TIMER_FETCH BIGINT unsigned not null,"
-                      "MIN_TIMER_FETCH BIGINT unsigned not null,"
-                      "AVG_TIMER_FETCH BIGINT unsigned not null,"
-                      "MAX_TIMER_FETCH BIGINT unsigned not null,"
-                      "COUNT_INSERT BIGINT unsigned not null,"
-                      "SUM_TIMER_INSERT BIGINT unsigned not null,"
-                      "MIN_TIMER_INSERT BIGINT unsigned not null,"
-                      "AVG_TIMER_INSERT BIGINT unsigned not null,"
-                      "MAX_TIMER_INSERT BIGINT unsigned not null,"
-                      "COUNT_UPDATE BIGINT unsigned not null,"
-                      "SUM_TIMER_UPDATE BIGINT unsigned not null,"
-                      "MIN_TIMER_UPDATE BIGINT unsigned not null,"
-                      "AVG_TIMER_UPDATE BIGINT unsigned not null,"
-                      "MAX_TIMER_UPDATE BIGINT unsigned not null,"
-                      "COUNT_DELETE BIGINT unsigned not null,"
-                      "SUM_TIMER_DELETE BIGINT unsigned not null,"
-                      "MIN_TIMER_DELETE BIGINT unsigned not null,"
-                      "AVG_TIMER_DELETE BIGINT unsigned not null,"
-                      "MAX_TIMER_DELETE BIGINT unsigned not null)") }
+                      "OBJECT_TYPE VARCHAR(64) comment 'Since this table records waits by table, always set to TABLE.',"
+                      "OBJECT_SCHEMA VARCHAR(64) comment 'Schema name.',"
+                      "OBJECT_NAME VARCHAR(64) comment 'Table name.',"
+                      "COUNT_STAR BIGINT unsigned not null comment 'Number of summarized events and the sum of the x_READ and x_WRITE columns.',"
+                      "SUM_TIMER_WAIT BIGINT unsigned not null comment 'Total wait time of the summarized events that are timed.',"
+                      "MIN_TIMER_WAIT BIGINT unsigned not null comment 'Minimum wait time of the summarized events that are timed.',"
+                      "AVG_TIMER_WAIT BIGINT unsigned not null comment 'Average wait time of the summarized events that are timed.',"
+                      "MAX_TIMER_WAIT BIGINT unsigned not null comment 'Maximum wait time of the summarized events that are timed.',"
+                      "COUNT_READ BIGINT unsigned not null comment 'Number of all read operations, and the sum of the equivalent x_FETCH columns.',"
+                      "SUM_TIMER_READ BIGINT unsigned not null comment 'Total wait time of all read operations that are timed.',"
+                      "MIN_TIMER_READ BIGINT unsigned not null comment 'Minimum wait time of all read operations that are timed.',"
+                      "AVG_TIMER_READ BIGINT unsigned not null comment 'Average wait time of all read operations that are timed.',"
+                      "MAX_TIMER_READ BIGINT unsigned not null comment 'Maximum wait time of all read operations that are timed.',"
+                      "COUNT_WRITE BIGINT unsigned not null comment 'Number of all write operations, and the sum of the equivalent x_INSERT, x_UPDATE and x_DELETE columns.',"
+                      "SUM_TIMER_WRITE BIGINT unsigned not null comment 'Total wait time of all write operations that are timed.',"
+                      "MIN_TIMER_WRITE BIGINT unsigned not null comment 'Minimum wait time of all write operations that are timed.',"
+                      "AVG_TIMER_WRITE BIGINT unsigned not null comment 'Average wait time of all write operations that are timed.',"
+                      "MAX_TIMER_WRITE BIGINT unsigned not null comment 'Maximum wait time of all write operations that are timed.',"
+                      "COUNT_FETCH BIGINT unsigned not null comment 'Number of all fetch operations.',"
+                      "SUM_TIMER_FETCH BIGINT unsigned not null comment 'Total wait time of all fetch operations that are timed.',"
+                      "MIN_TIMER_FETCH BIGINT unsigned not null comment 'Minimum wait time of all fetch operations that are timed.',"
+                      "AVG_TIMER_FETCH BIGINT unsigned not null comment 'Average wait time of all fetch operations that are timed.',"
+                      "MAX_TIMER_FETCH BIGINT unsigned not null comment 'Maximum wait time of all fetch operations that are timed.',"
+                      "COUNT_INSERT BIGINT unsigned not null comment 'Number of all insert operations.',"
+                      "SUM_TIMER_INSERT BIGINT unsigned not null comment 'Total wait time of all insert operations that are timed.',"
+                      "MIN_TIMER_INSERT BIGINT unsigned not null comment 'Minimum wait time of all insert operations that are timed.',"
+                      "AVG_TIMER_INSERT BIGINT unsigned not null comment 'Average wait time of all insert operations that are timed.',"
+                      "MAX_TIMER_INSERT BIGINT unsigned not null comment 'Maximum wait time of all insert operations that are timed.',"
+                      "COUNT_UPDATE BIGINT unsigned not null comment 'Number of all update operations.',"
+                      "SUM_TIMER_UPDATE BIGINT unsigned not null comment 'Total wait time of all update operations that are timed.',"
+                      "MIN_TIMER_UPDATE BIGINT unsigned not null comment 'Minimum wait time of all update operations that are timed.',"
+                      "AVG_TIMER_UPDATE BIGINT unsigned not null comment 'Average wait time of all update operations that are timed.',"
+                      "MAX_TIMER_UPDATE BIGINT unsigned not null comment 'Maximum wait time of all update operations that are timed.',"
+                      "COUNT_DELETE BIGINT unsigned not null comment 'Number of all delete operations.',"
+                      "SUM_TIMER_DELETE BIGINT unsigned not null comment 'Total wait time of all delete operations that are timed.',"
+                      "MIN_TIMER_DELETE BIGINT unsigned not null comment 'Minimum wait time of all delete operations that are timed.',"
+                      "AVG_TIMER_DELETE BIGINT unsigned not null comment 'Average wait time of all delete operations that are timed.',"
+                      "MAX_TIMER_DELETE BIGINT unsigned not null comment 'Maximum wait time of all delete operations that are timed.')") }
 };
 
 PFS_engine_table*

storage/perfschema/table_tlws_by_table.cc

@@ -49,79 +49,79 @@ table_tlws_by_table::m_share=
   sizeof(PFS_simple_index),
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE table_lock_waits_summary_by_table("
-                      "OBJECT_TYPE VARCHAR(64),"
-                      "OBJECT_SCHEMA VARCHAR(64),"
-                      "OBJECT_NAME VARCHAR(64),"
-                      "COUNT_STAR BIGINT unsigned not null,"
-                      "SUM_TIMER_WAIT BIGINT unsigned not null,"
-                      "MIN_TIMER_WAIT BIGINT unsigned not null,"
-                      "AVG_TIMER_WAIT BIGINT unsigned not null,"
-                      "MAX_TIMER_WAIT BIGINT unsigned not null,"
-                      "COUNT_READ BIGINT unsigned not null,"
-                      "SUM_TIMER_READ BIGINT unsigned not null,"
-                      "MIN_TIMER_READ BIGINT unsigned not null,"
-                      "AVG_TIMER_READ BIGINT unsigned not null,"
-                      "MAX_TIMER_READ BIGINT unsigned not null,"
-                      "COUNT_WRITE BIGINT unsigned not null,"
-                      "SUM_TIMER_WRITE BIGINT unsigned not null,"
-                      "MIN_TIMER_WRITE BIGINT unsigned not null,"
-                      "AVG_TIMER_WRITE BIGINT unsigned not null,"
-                      "MAX_TIMER_WRITE BIGINT unsigned not null,"
-                      "COUNT_READ_NORMAL BIGINT unsigned not null,"
-                      "SUM_TIMER_READ_NORMAL BIGINT unsigned not null,"
-                      "MIN_TIMER_READ_NORMAL BIGINT unsigned not null,"
-                      "AVG_TIMER_READ_NORMAL BIGINT unsigned not null,"
-                      "MAX_TIMER_READ_NORMAL BIGINT unsigned not null,"
-                      "COUNT_READ_WITH_SHARED_LOCKS BIGINT unsigned not null,"
-                      "SUM_TIMER_READ_WITH_SHARED_LOCKS BIGINT unsigned not null,"
-                      "MIN_TIMER_READ_WITH_SHARED_LOCKS BIGINT unsigned not null,"
-                      "AVG_TIMER_READ_WITH_SHARED_LOCKS BIGINT unsigned not null,"
-                      "MAX_TIMER_READ_WITH_SHARED_LOCKS BIGINT unsigned not null,"
-                      "COUNT_READ_HIGH_PRIORITY BIGINT unsigned not null,"
-                      "SUM_TIMER_READ_HIGH_PRIORITY BIGINT unsigned not null,"
-                      "MIN_TIMER_READ_HIGH_PRIORITY BIGINT unsigned not null,"
-                      "AVG_TIMER_READ_HIGH_PRIORITY BIGINT unsigned not null,"
-                      "MAX_TIMER_READ_HIGH_PRIORITY BIGINT unsigned not null,"
-                      "COUNT_READ_NO_INSERT BIGINT unsigned not null,"
-                      "SUM_TIMER_READ_NO_INSERT BIGINT unsigned not null,"
-                      "MIN_TIMER_READ_NO_INSERT BIGINT unsigned not null,"
-                      "AVG_TIMER_READ_NO_INSERT BIGINT unsigned not null,"
-                      "MAX_TIMER_READ_NO_INSERT BIGINT unsigned not null,"
-                      "COUNT_READ_EXTERNAL BIGINT unsigned not null,"
-                      "SUM_TIMER_READ_EXTERNAL BIGINT unsigned not null,"
-                      "MIN_TIMER_READ_EXTERNAL BIGINT unsigned not null,"
-                      "AVG_TIMER_READ_EXTERNAL BIGINT unsigned not null,"
-                      "MAX_TIMER_READ_EXTERNAL BIGINT unsigned not null,"
-                      "COUNT_WRITE_ALLOW_WRITE BIGINT unsigned not null,"
-                      "SUM_TIMER_WRITE_ALLOW_WRITE BIGINT unsigned not null,"
-                      "MIN_TIMER_WRITE_ALLOW_WRITE BIGINT unsigned not null,"
-                      "AVG_TIMER_WRITE_ALLOW_WRITE BIGINT unsigned not null,"
-                      "MAX_TIMER_WRITE_ALLOW_WRITE BIGINT unsigned not null,"
-                      "COUNT_WRITE_CONCURRENT_INSERT BIGINT unsigned not null,"
-                      "SUM_TIMER_WRITE_CONCURRENT_INSERT BIGINT unsigned not null,"
-                      "MIN_TIMER_WRITE_CONCURRENT_INSERT BIGINT unsigned not null,"
-                      "AVG_TIMER_WRITE_CONCURRENT_INSERT BIGINT unsigned not null,"
-                      "MAX_TIMER_WRITE_CONCURRENT_INSERT BIGINT unsigned not null,"
-                      "COUNT_WRITE_DELAYED BIGINT unsigned not null,"
-                      "SUM_TIMER_WRITE_DELAYED BIGINT unsigned not null,"
-                      "MIN_TIMER_WRITE_DELAYED BIGINT unsigned not null,"
-                      "AVG_TIMER_WRITE_DELAYED BIGINT unsigned not null,"
-                      "MAX_TIMER_WRITE_DELAYED BIGINT unsigned not null,"
-                      "COUNT_WRITE_LOW_PRIORITY BIGINT unsigned not null,"
-                      "SUM_TIMER_WRITE_LOW_PRIORITY BIGINT unsigned not null,"
-                      "MIN_TIMER_WRITE_LOW_PRIORITY BIGINT unsigned not null,"
-                      "AVG_TIMER_WRITE_LOW_PRIORITY BIGINT unsigned not null,"
-                      "MAX_TIMER_WRITE_LOW_PRIORITY BIGINT unsigned not null,"
-                      "COUNT_WRITE_NORMAL BIGINT unsigned not null,"
-                      "SUM_TIMER_WRITE_NORMAL BIGINT unsigned not null,"
-                      "MIN_TIMER_WRITE_NORMAL BIGINT unsigned not null,"
-                      "AVG_TIMER_WRITE_NORMAL BIGINT unsigned not null,"
-                      "MAX_TIMER_WRITE_NORMAL BIGINT unsigned not null,"
-                      "COUNT_WRITE_EXTERNAL BIGINT unsigned not null,"
-                      "SUM_TIMER_WRITE_EXTERNAL BIGINT unsigned not null,"
-                      "MIN_TIMER_WRITE_EXTERNAL BIGINT unsigned not null,"
-                      "AVG_TIMER_WRITE_EXTERNAL BIGINT unsigned not null,"
-                      "MAX_TIMER_WRITE_EXTERNAL BIGINT unsigned not null)") }
+                      "OBJECT_TYPE VARCHAR(64) comment 'Since this table records waits by table, always set to TABLE.',"
+                      "OBJECT_SCHEMA VARCHAR(64) comment 'Schema name.',"
+                      "OBJECT_NAME VARCHAR(64) comment 'Table name.',"
+                      "COUNT_STAR BIGINT unsigned not null comment 'Number of summarized events and the sum of the x_READ and x_WRITE columns.',"
+                      "SUM_TIMER_WAIT BIGINT unsigned not null comment 'Total wait time of the summarized events that are timed.',"
+                      "MIN_TIMER_WAIT BIGINT unsigned not null comment 'Minimum wait time of the summarized events that are timed.',"
+                      "AVG_TIMER_WAIT BIGINT unsigned not null comment 'Average wait time of the summarized events that are timed.',"
+                      "MAX_TIMER_WAIT BIGINT unsigned not null comment 'Maximum wait time of the summarized events that are timed.',"
+                      "COUNT_READ BIGINT unsigned not null comment 'Number of all read operations, and the sum of the equivalent x_READ_NORMAL, x_READ_WITH_SHARED_LOCKS, x_READ_HIGH_PRIORITY and x_READ_NO_INSERT columns.',"
+                      "SUM_TIMER_READ BIGINT unsigned not null comment 'Total wait time of all read operations that are timed.',"
+                      "MIN_TIMER_READ BIGINT unsigned not null comment 'Minimum wait time of all read operations that are timed.',"
+                      "AVG_TIMER_READ BIGINT unsigned not null comment 'Average wait time of all read operations that are timed.',"
+                      "MAX_TIMER_READ BIGINT unsigned not null comment 'Maximum wait time of all read operations that are timed.',"
+                      "COUNT_WRITE BIGINT unsigned not null comment 'Number of all write operations, and the sum of the equivalent x_WRITE_ALLOW_WRITE, x_WRITE_CONCURRENT_INSERT, x_WRITE_DELAYED, x_WRITE_LOW_PRIORITY and x_WRITE_NORMAL columns.',"
+                      "SUM_TIMER_WRITE BIGINT unsigned not null comment 'Total wait time of all write operations that are timed.',"
+                      "MIN_TIMER_WRITE BIGINT unsigned not null comment 'Minimum wait time of all write operations that are timed.',"
+                      "AVG_TIMER_WRITE BIGINT unsigned not null comment 'Average wait time of all write operations that are timed.',"
+                      "MAX_TIMER_WRITE BIGINT unsigned not null comment 'Maximum wait time of all write operations that are timed.',"
+                      "COUNT_READ_NORMAL BIGINT unsigned not null comment 'Number of all internal read normal locks.',"
+                      "SUM_TIMER_READ_NORMAL BIGINT unsigned not null comment 'Total wait time of all internal read normal locks that are timed.',"
+                      "MIN_TIMER_READ_NORMAL BIGINT unsigned not null comment 'Minimum wait time of all internal read normal locks that are timed.',"
+                      "AVG_TIMER_READ_NORMAL BIGINT unsigned not null comment 'Average wait time of all internal read normal locks that are timed.',"
+                      "MAX_TIMER_READ_NORMAL BIGINT unsigned not null comment 'Maximum wait time of all internal read normal locks that are timed.',"
+                      "COUNT_READ_WITH_SHARED_LOCKS BIGINT unsigned not null comment 'Number of all internal read with shared locks.',"
+                      "SUM_TIMER_READ_WITH_SHARED_LOCKS BIGINT unsigned not null comment 'Total wait time of all internal read with shared locks that are timed.',"
+                      "MIN_TIMER_READ_WITH_SHARED_LOCKS BIGINT unsigned not null comment 'Minimum wait time of all internal read with shared locks that are timed.',"
+                      "AVG_TIMER_READ_WITH_SHARED_LOCKS BIGINT unsigned not null comment 'Average wait time of all internal read with shared locks that are timed.',"
+                      "MAX_TIMER_READ_WITH_SHARED_LOCKS BIGINT unsigned not null comment 'Maximum wait time of all internal read with shared locks that are timed.',"
+                      "COUNT_READ_HIGH_PRIORITY BIGINT unsigned not null comment 'Number of all internal read high priority locks.',"
+                      "SUM_TIMER_READ_HIGH_PRIORITY BIGINT unsigned not null comment 'Total wait time of all internal read high priority locks that are timed.',"
+                      "MIN_TIMER_READ_HIGH_PRIORITY BIGINT unsigned not null comment 'Minimum wait time of all internal read high priority locks that are timed.',"
+                      "AVG_TIMER_READ_HIGH_PRIORITY BIGINT unsigned not null comment 'Average wait time of all internal read high priority locks that are timed.',"
+                      "MAX_TIMER_READ_HIGH_PRIORITY BIGINT unsigned not null comment 'Maximum wait time of all internal read high priority locks that are timed.',"
+                      "COUNT_READ_NO_INSERT BIGINT unsigned not null comment 'Number of all internal read no insert locks.',"
+                      "SUM_TIMER_READ_NO_INSERT BIGINT unsigned not null comment 'Total wait time of all internal read no insert locks that are timed.',"
+                      "MIN_TIMER_READ_NO_INSERT BIGINT unsigned not null comment 'Minimum wait time of all internal read no insert locks that are timed.',"
+                      "AVG_TIMER_READ_NO_INSERT BIGINT unsigned not null comment 'Average wait time of all internal read no insert locks that are timed.',"
+                      "MAX_TIMER_READ_NO_INSERT BIGINT unsigned not null comment 'Maximum wait time of all internal read no insert locks that are timed.',"
+                      "COUNT_READ_EXTERNAL BIGINT unsigned not null comment 'Number of all external read locks.',"
+                      "SUM_TIMER_READ_EXTERNAL BIGINT unsigned not null comment 'Total wait time of all external read locks that are timed.',"
+                      "MIN_TIMER_READ_EXTERNAL BIGINT unsigned not null comment 'Minimum wait time of all external read locks that are timed.',"
+                      "AVG_TIMER_READ_EXTERNAL BIGINT unsigned not null comment 'Average wait time of all external read locks that are timed.',"
+                      "MAX_TIMER_READ_EXTERNAL BIGINT unsigned not null comment 'Maximum wait time of all external read locks that are timed.',"
+                      "COUNT_WRITE_ALLOW_WRITE BIGINT unsigned not null comment 'Number of all internal read normal locks.',"
+                      "SUM_TIMER_WRITE_ALLOW_WRITE BIGINT unsigned not null comment 'Total wait time of all internal write allow write locks that are timed.',"
+                      "MIN_TIMER_WRITE_ALLOW_WRITE BIGINT unsigned not null comment 'Minimum wait time of all internal write allow write locks that are timed.',"
+                      "AVG_TIMER_WRITE_ALLOW_WRITE BIGINT unsigned not null comment 'Average wait time of all internal write allow write locks that are timed.',"
+                      "MAX_TIMER_WRITE_ALLOW_WRITE BIGINT unsigned not null comment 'Maximum wait time of all internal write allow write locks that are timed.',"
+                      "COUNT_WRITE_CONCURRENT_INSERT BIGINT unsigned not null comment 'Number of all internal concurrent insert write locks.',"
+                      "SUM_TIMER_WRITE_CONCURRENT_INSERT BIGINT unsigned not null comment 'Total wait time of all internal concurrent insert write locks that are timed.',"
+                      "MIN_TIMER_WRITE_CONCURRENT_INSERT BIGINT unsigned not null comment 'Minimum wait time of all internal concurrent insert write locks that are timed.',"
+                      "AVG_TIMER_WRITE_CONCURRENT_INSERT BIGINT unsigned not null comment 'Average wait time of all internal concurrent insert write locks that are timed.',"
+                      "MAX_TIMER_WRITE_CONCURRENT_INSERT BIGINT unsigned not null comment 'Maximum wait time of all internal concurrent insert write locks that are timed.',"
+                      "COUNT_WRITE_DELAYED BIGINT unsigned not null comment 'Number of all internal write delayed locks.',"
+                      "SUM_TIMER_WRITE_DELAYED BIGINT unsigned not null comment 'Total wait time of all internal write delayed locks that are timed.',"
+                      "MIN_TIMER_WRITE_DELAYED BIGINT unsigned not null comment 'Minimum wait time of all internal write delayed locks that are timed.',"
+                      "AVG_TIMER_WRITE_DELAYED BIGINT unsigned not null comment 'Average wait time of all internal write delayed locks that are timed.',"
+                      "MAX_TIMER_WRITE_DELAYED BIGINT unsigned not null comment 'Maximum wait time of all internal write delayed locks that are timed.',"
+                      "COUNT_WRITE_LOW_PRIORITY BIGINT unsigned not null comment 'Number of all internal write low priority locks.',"
+                      "SUM_TIMER_WRITE_LOW_PRIORITY BIGINT unsigned not null comment 'Total wait time of all internal write low priority locks that are timed.',"
+                      "MIN_TIMER_WRITE_LOW_PRIORITY BIGINT unsigned not null comment 'Minimum wait time of all internal write low priority locks that are timed.',"
+                      "AVG_TIMER_WRITE_LOW_PRIORITY BIGINT unsigned not null comment 'Average wait time of all internal write low priority locks that are timed.',"
+                      "MAX_TIMER_WRITE_LOW_PRIORITY BIGINT unsigned not null comment 'Maximum wait time of all internal write low priority locks that are timed.',"
+                      "COUNT_WRITE_NORMAL BIGINT unsigned not null comment 'Number of all internal write normal locks.',"
+                      "SUM_TIMER_WRITE_NORMAL BIGINT unsigned not null comment 'Total wait time of all internal write normal locks that are timed.',"
+                      "MIN_TIMER_WRITE_NORMAL BIGINT unsigned not null comment 'Minimum wait time of all internal write normal locks that are timed.',"
+                      "AVG_TIMER_WRITE_NORMAL BIGINT unsigned not null comment 'Average wait time of all internal write normal locks that are timed.',"
+                      "MAX_TIMER_WRITE_NORMAL BIGINT unsigned not null comment 'Maximum wait time of all internal write normal locks that are timed.',"
+                      "COUNT_WRITE_EXTERNAL BIGINT unsigned not null comment 'Number of all external write locks.',"
+                      "SUM_TIMER_WRITE_EXTERNAL BIGINT unsigned not null comment 'Total wait time of all external write locks that are timed.',"
+                      "MIN_TIMER_WRITE_EXTERNAL BIGINT unsigned not null comment 'Minimum wait time of all external write locks that are timed.',"
+                      "AVG_TIMER_WRITE_EXTERNAL BIGINT unsigned not null comment 'Average wait time of all external write locks that are timed.',"
+                      "MAX_TIMER_WRITE_EXTERNAL BIGINT unsigned not null comment 'Maximum wait time of all external write locks that are timed.')") }
 };
 
 PFS_engine_table*

storage/perfschema/table_users.cc

@@ -44,9 +44,9 @@ table_users::m_share=
   sizeof(PFS_simple_index), /* ref length */
   &m_table_lock,
   { C_STRING_WITH_LEN("CREATE TABLE users("
-                      "USER CHAR(" STRINGIFY_ARG(USERNAME_CHAR_LENGTH) ") collate utf8_bin default null,"
-                      "CURRENT_CONNECTIONS bigint not null,"
-                      "TOTAL_CONNECTIONS bigint not null)") }
+                      "USER CHAR(" STRINGIFY_ARG(USERNAME_CHAR_LENGTH) ") collate utf8_bin default null comment 'The connection''s client user name for the connection, or NULL if an internal thread.',"
+                      "CURRENT_CONNECTIONS bigint not null comment 'Current connections for the user.',"
+                      "TOTAL_CONNECTIONS bigint not null comment 'Total connections for the user.')") }
 };
 
 PFS_engine_table* table_users::create()