The original code comes, as far as I know, from Google (Mark Callaghan's team) with additional work from Percona, Ourdelta and Weldon Whipple.

This code provides the same functionallity, but with a lot of changes to make it faster and better fit the MariaDB infrastucture.

Added new status variables:
- Com_show_client_statistics, Com_show_index_statistics, Com_show_table_statistics, Com_show_user_statistics
- Access_denied_errors, Busy_time (clock time), Binlog_bytes_written, Cpu_time, Empty_queries, Rows_sent, Rows_read

Added new variable / startup option 'userstat' to control if user statistics should be enabled or not

Added my_getcputime(); Returns cpu time used by this thread.
New FLUSH commands:
- FLUSH SLOW QUERY LOG
- FLUSH TABLE_STATISTICS
- FLUSH INDEX_STATISTICS
- FLUSH USER_STATISTICS
- FLUSH CLIENT_STATISTICS

New SHOW commands:
- SHOW CLIENT_STATISTICS
- SHOW USER_STATISTICS
- SHOW TABLE_STATISTICS
- SHOW INDEX_STATISTICS

New Information schemas:
- CLIENT_STATISTICS
- USER_STATISTICS
- INDEX_STATISTICS
- TABLE_STATISTICS

Added support for all new flush commands to mysqladmin

Added handler::ha_... wrappers for all handler read calls to do statistics counting
- Changed all code to use new ha_... calls
- Count number of read rows, changed rows and rows read trough an index

Added counting of number of bytes sent to binary log (status variable Binlog_bytes_written)
Added counting of access denied errors (status variable Access_denied_erors)

Bugs fixed:
- Fixed bug in add_to_status() and add_diff_to_status() where longlong variables where threated as long
- CLOCK_GETTIME was not propely working on Linuxm

client/mysqladmin.cc:
  Added support for all new flush commmands and some common combinations:
  
  flush-slow-log
  flush-table-statistics
  flush-index-statistics
  flush-user-statistics
  flush-client-statistics
  flush-all-status
  flush-all-statistics
configure.in:
  Added checking if clock_gettime needs the librt.
  (Fixes Bug #37639 clock_gettime is never used/enabled in Linux/Unix)
include/my_sys.h:
  Added my_getcputime()
include/mysql_com.h:
  Added LIST_PROCESS_HOST_LEN & new REFRESH target defines
mysql-test/r/information_schema.result:
  New information schema tables added
mysql-test/r/information_schema_all_engines.result:
  New information schema tables added
mysql-test/r/information_schema_db.result:
  New information schema tables added
mysql-test/r/log_slow.result:
  Added testing that flosh slow query logs is accepted
mysql-test/r/status_user.result:
  Basic testing of user, client, table and index statistics
mysql-test/t/log_slow.test:
  Added testing that flosh slow query logs is accepted
mysql-test/t/status_user-master.opt:
  Ensure that we get a fresh restart before running status_user.test
mysql-test/t/status_user.test:
  Basic testing of user, client, table and index statistics
mysys/my_getsystime.c:
  Added my_getcputime()
  Returns cpu time used by this thread.
sql/authors.h:
  Updated authors to have core and original MySQL developers first.
sql/event_data_objects.cc:
  Updated call to mysql_reset_thd_for_next_command()
sql/event_db_repository.cc:
  Changed to use new ha_... calls
sql/filesort.cc:
  Changed to use new ha_... calls
sql/ha_partition.cc:
  Changed to use new ha_... calls
  Fixed comment syntax
sql/handler.cc:
  Changed to use new ha_... calls
  Reset table statistics
  Added code to update global table and index status
  Added counting of rows changed
sql/handler.h:
  Added table and index statistics variables
  Added function reset_statistics()
  Added handler::ha_... wrappers for all handler read calls to do statistics counting
  Protected all normal read calls to ensure we use the new calls in the server.
  Made ha_partition a friend class so that partition code can call the old read functions
sql/item_subselect.cc:
  Changed to use new ha_... calls
sql/lex.h:
  Added keywords for new information schema tables and flush commands
sql/log.cc:
  Added flush_slow_log()
  Added counting of number of bytes sent to binary log
  Removed not needed test of thd (It's used before, so it's safe to use)
  Added THD object to MYSQL_BIN_LOG::write_cache() to simplify statistics counting
sql/log.h:
  Added new parameter to write_cache()
  Added flush_slow_log() functions.
sql/log_event.cc:
  Updated call to mysql_reset_thd_for_next_command()
  Changed to use new ha_... calls
sql/log_event_old.cc:
  Updated call to mysql_reset_thd_for_next_command()
  Changed to use new ha_... calls
sql/mysql_priv.h:
  Updated call to mysql_reset_thd_for_next_command()
  Added new statistics functions and variables needed by these.
sql/mysqld.cc:
  Added new statistics variables and structures to handle these
  Added new status variables:
  - Com_show_client_statistics, Com_show_index_statistics, Com_show_table_statistics, Com_show_user_statistics
  - Access_denied_errors, Busy_time (clock time), Binlog_bytes_written, Cpu_time, Empty_queries, Rows_set, Rows_read
  Added new option 'userstat' to control if user statistics should be enabled or not
sql/opt_range.cc:
  Changed to use new ha_... calls
sql/opt_range.h:
  Changed to use new ha_... calls
sql/opt_sum.cc:
  Changed to use new ha_... calls
sql/records.cc:
  Changed to use new ha_... calls
sql/set_var.cc:
  Added variable 'userstat'
sql/sp.cc:
  Changed to use new ha_... calls
sql/sql_acl.cc:
  Changed to use new ha_... calls
  Added counting of access_denied_errors
sql/sql_base.cc:
  Added call to statistics functions
sql/sql_class.cc:
  Added usage of org_status_var, to store status variables at start of command
  Added functions THD::update_stats(), THD::update_all_stats()
  Fixed bug in add_to_status() and add_diff_to_status() where longlong variables where threated as long
sql/sql_class.h:
  Added new status variables to status_var
  Moved variables that was not ulong in status_var last.
  Added variables to THD for storing temporary values during statistics counting
sql/sql_connect.cc:
  Variables and functions to calculate user and client statistics
  Added counting of access_denied_errors and lost_connections
sql/sql_cursor.cc:
  Changed to use new ha_... calls
sql/sql_handler.cc:
  Changed to use new ha_... calls
sql/sql_help.cc:
  Changed to use new ha_... calls
sql/sql_insert.cc:
  Changed to use new ha_... calls
sql/sql_lex.h:
  Added SQLCOM_SHOW_USER_STATS, SQLCOM_SHOW_TABLE_STATS, SQLCOM_SHOW_INDEX_STATS, SQLCOM_SHOW_CLIENT_STATS
sql/sql_parse.cc:
  Added handling of:
  - SHOW CLIENT_STATISTICS
  - SHOW USER_STATISTICS
  - SHOW TABLE_STATISTICS
  - SHOW INDEX_STATISTICS
  Added handling of new FLUSH commands:
  - FLUSH SLOW QUERY LOGS
  - FLUSH TABLE_STATISTICS
  - FLUSH INDEX_STATISTICS
  - FLUSH USER_STATISTICS
  - FLUSH CLIENT_STATISTICS
  Added THD parameter to mysql_reset_thd_for_next_command()
  Added initialization and calls to user statistics functions
  Added increment of statistics variables empty_queries, rows_sent and access_denied_errors.
  Added counting of cpu time per query
sql/sql_plugin.cc:
  Changed to use new ha_... calls
sql/sql_prepare.cc:
  Updated call to mysql_reset_thd_for_next_command()
sql/sql_select.cc:
  Changed to use new ha_... calls
  Indentation changes
sql/sql_servers.cc:
  Changed to use new ha_... calls
sql/sql_show.cc:
  Added counting of access denied errors
  Added function for new information schema tables:
  - CLIENT_STATISTICS
  - USER_STATISTICS
  - INDEX_STATISTICS
  - TABLE_STATISTICS
  Changed to use new ha_... calls
sql/sql_table.cc:
  Changed to use new ha_... calls
sql/sql_udf.cc:
  Changed to use new ha_... calls
sql/sql_update.cc:
  Changed to use new ha_... calls
sql/sql_yacc.yy:
  Add new show and flush commands
sql/structs.h:
  Add name_length to KEY to avoid some strlen
  Added cache_name to KEY for fast storage of keyvalue in cache
  Added structs USER_STATS, TABLE_STATS, INDEX_STATS
  Added function prototypes for statistics functions
sql/table.cc:
  Store db+table+index name into keyinfo->cache_name
sql/table.h:
  Added new information schema tables
sql/tztime.cc:
  Changed to use new ha_... calls

This fixes a race condition in the test system

mysql-test/include/maria_empty_logs.inc:
  Added comment
mysql-test/include/wait_for_status_var.inc:
  Fixed type in variable name. Add ' around variables for better error message
mysql-test/mysql-test-run.pl:
  Remove -skip-falcon (not to be used), add skip-pbxt to bootstrap
mysql-test/suite/maria/t/maria_showlog_error-master.opt:
  Force restart before maria_showlog_error to get rid of status from previous connection

while waiting for output): attempt 2

while waiting for output)

Remove the run of the parts suite (as it is now included in default list of suite).
Add run of PBXT.

binary distribution zips.

Problem was the use of SHOW PROCESSLIST. This is not fully functional in
embedded server, STATE is hardcoded to "Writing to net".

Fixed using --replace_result for STATE.

The test is supposed to provoke a deadlock, to test a crash of the server in
some deadlock scenarios.

The problem is that in recent version of MySQL, no deadlock occurs. It is not
clear why a deadlock should be expected. One transaction does an insert+delete
on primary key value 1 in table t2. The other transaction does an insert on
primary key value 123. There seems no reason that these should conflict, so
there is no deadlock.

(Presumably an earlier version did get a deadlock due to maybe taking excessive
locks on the insert+delete of primary key value 1. The table has only one row,
so maybe a different locking was used ("Impossible WHERE noticed after reading
const tables"))

Fix is to have transaction 1 lock PK 1 and transaction 2 lock PK 123. Then have
transaction 2 access PK 1 (wait) and transaction 1 access PK 123 (deadlock).

It has been checked that this modified test case still crashes the server in
the same way prior to fix of the original bug (Bug#24989).


mysql-test/include/read_many_rows.inc:
  Provoke deadlock on same PK value in the two transactions to ensure that the
  deadlock does occur independently on whatever execution plan is chosen.
mysql-test/r/read_many_rows_innodb.result:
  Result file update.

Some result updates necessary due to extra tables and columns added in
information_schema in MariaDB (XtraDB, PBXT, microsec_process).

Also fix bad merge of two result files; apparently the test case was merged,
but the result file was not.

mysql-test/suite/funcs_1/datadict/processlist_priv.inc:
  Handle the new TIME_MS column in information_schema.processlist.
mysql-test/suite/funcs_1/datadict/processlist_val.inc:
  Handle the new TIME_MS column in information_schema.processlist.
mysql-test/suite/funcs_1/r/is_columns_is.result:
  Handle new tables in information_schema.
mysql-test/suite/funcs_1/r/is_tables_is.result:
  Handle new tables in information_schema.
mysql-test/suite/funcs_1/r/is_tables_myisam.result:
  Fix previous bad merge; apparently this file was not merged along with test changes.
mysql-test/suite/funcs_1/r/processlist_priv_no_prot.result:
  Handle the new TIME_MS column in information_schema.processlist.
mysql-test/suite/funcs_1/r/processlist_val_no_prot.result:
  Fix previous bad merge; apparently this file was not merged along with test changes.
  Also handle the new TIME_MS column in INFORMATION_SCHEMA.PROCESSLIST.
mysql-test/suite/funcs_1/t/is_columns_is.test:
  Since result file includes PBXT information_schema tables, we need PBXT to run this test.

Fix some connect options to work with embedded.

Disable in --embedded tests that rely on connecting to mysqld externally by
spawning mysqltest.

Disable in --embedded tests that rely on the mysqltest --list_files command,
which does not seem to work properly in --embedded.

mysql-test/suite/parts/t/partition_alter1_1_2_innodb.test:
  Disable in --embedded tests that rely on connecting to mysqld externally by
  spawning mysqltest.
mysql-test/suite/parts/t/partition_alter1_1_2_myisam.test:
  Disable in --embedded tests that rely on connecting to mysqld externally by
  spawning mysqltest.
mysql-test/suite/parts/t/partition_alter1_1_innodb.test:
  Disable in --embedded tests that rely on connecting to mysqld externally by
  spawning mysqltest.
mysql-test/suite/parts/t/partition_alter1_1_myisam.test:
  Disable in --embedded tests that rely on connecting to mysqld externally by
  spawning mysqltest.
mysql-test/suite/parts/t/partition_alter1_2_innodb.test:
  Disable in --embedded tests that rely on connecting to mysqld externally by
  spawning mysqltest.
mysql-test/suite/parts/t/partition_alter1_2_myisam.test:
  Disable in --embedded tests that rely on connecting to mysqld externally by
  spawning mysqltest.
mysql-test/suite/parts/t/partition_alter2_1_innodb.test:
  Disable in --embedded tests that rely on connecting to mysqld externally by
  spawning mysqltest.
mysql-test/suite/parts/t/partition_alter2_1_maria.test:
  Disable in --embedded tests that rely on connecting to mysqld externally by
  spawning mysqltest.
mysql-test/suite/parts/t/partition_alter2_1_myisam.test:
  Disable in --embedded tests that rely on connecting to mysqld externally by
  spawning mysqltest.
mysql-test/suite/parts/t/partition_alter2_2_innodb.test:
  Disable in --embedded tests that rely on connecting to mysqld externally by
  spawning mysqltest.
mysql-test/suite/parts/t/partition_alter2_2_maria.test:
  Disable in --embedded tests that rely on connecting to mysqld externally by
  spawning mysqltest.
mysql-test/suite/parts/t/partition_alter2_2_myisam.test:
  Disable in --embedded tests that rely on connecting to mysqld externally by
  spawning mysqltest.
mysql-test/suite/parts/t/partition_alter3_innodb.test:
  Disable in --embedded tests that rely on the mysqltest --list_files command,
  which does not seem to work properly in --embedded.
mysql-test/suite/parts/t/partition_alter3_myisam.test:
  Disable in --embedded tests that rely on the mysqltest --list_files command,
  which does not seem to work properly in --embedded.
mysql-test/suite/parts/t/partition_alter4_innodb.test:
  Disable in --embedded tests that rely on connecting to mysqld externally by
  spawning mysqltest.
mysql-test/suite/parts/t/partition_alter4_myisam.test:
  Disable in --embedded tests that rely on connecting to mysqld externally by
  spawning mysqltest.
mysql-test/suite/parts/t/partition_basic_innodb.test:
  Disable in --embedded tests that rely on connecting to mysqld externally by
  spawning mysqltest.
mysql-test/suite/parts/t/partition_basic_myisam.test:
  Disable in --embedded tests that rely on connecting to mysqld externally by
  spawning mysqltest.
mysql-test/suite/parts/t/partition_basic_symlink_myisam.test:
  Disable in --embedded tests that rely on connecting to mysqld externally by
  spawning mysqltest.
mysql-test/suite/parts/t/partition_engine_innodb.test:
  Disable in --embedded tests that rely on connecting to mysqld externally by
  spawning mysqltest.
mysql-test/suite/parts/t/partition_engine_myisam.test:
  Disable in --embedded tests that rely on connecting to mysqld externally by
  spawning mysqltest.
mysql-test/suite/parts/t/partition_special_innodb.test:
  Fix some connect options to work with embedded.
mysql-test/suite/parts/t/partition_syntax_innodb.test:
  Disable in --embedded tests that rely on connecting to mysqld externally by
  spawning mysqltest.
mysql-test/suite/parts/t/partition_syntax_myisam.test:
  Disable in --embedded tests that rely on connecting to mysqld externally by
  spawning mysqltest.

The --enable_prepare_warnings allows to not discard warnings from autorepair
of crashed table in --ps-protocol mode.

Use this to properly fix the parts.partition_recover_myisam and
maria.maria-recover tests.

Add a test case for the new feature. This also adds missing test coverage
for the case where the same warning is thrown in both prepare and execute
phase.


client/mysqltest.cc:
  Implement new commands --enable-prepare_warnings and --disable_prepare_warnings.
mysql-test/r/mysqltest_ps.result:
  Add test case for new --enable_prepare_warning mysqltest command.
mysql-test/suite/maria/t/maria-recover.test:
  Better fix of test case using new --enable_prepare_warnings command.
mysql-test/suite/parts/t/partition_recover_myisam.test:
  Fix test failure in --ps-protocol mode.
mysql-test/t/mysqltest_ps.test:
  Add test case for new --enable_prepare_warning mysqltest command.

- Include maria_chk and other maria binaries
- Include sql/$TARGET/mysqld.lib, like mainline does (but what is that useful for?)
- Don't include my_safe_{process,kill} garbage.
- call '/bin/find', not just 'find' is that is some incompatible windows command.

 - Don't need any m1 prefix for the first release based on given MySQL
   version number.

 - Fix mysql-test-run to understand that some stuff is installed under
   share/mariadb rather than share/mysql.

MBUG#442254: mysql-test-run --embedded fails on Windows with: ERROR: .opt file references 'EXAMPLE_PLUGIN_OPT'
- Fix suggested by Kristian on review: ignore the test using mtr's facilities

- Part 2. make it really work.

- Update EXPLAIN results after table elimination
- mysqlslap now specifies 'Engine=' in CREATE TABLE instead of using 
  SET storage_engine=...
- For some reason, mysqltest logs "connect" command differently when PBXT
  is the default storage engine. This is probably a bug in mysqltest which
  we can't be bothered to investigate at the moment, so add --replace

mysql-test/suite/pbxt/r/connect.result:
  Fix pbxt test suite failures:
  - For some reason, mysqltest logs "connect" command differently when PBXT
    is the default storage engine. This is probably a bug in mysqltest which
    we can't be bothered to investigate at the moment, so add --replace
mysql-test/suite/pbxt/r/mysqlslap.result:
  Fix pbxt test suite failures:
  - mysqlslap now specifies 'Engine=' in CREATE TABLE instead of using 
    SET storage_engine=...
mysql-test/suite/pbxt/r/ps_11bugs.result:
  Fix pbxt test suite failures:
  - Update EXPLAIN results after table elimination
mysql-test/suite/pbxt/r/select.result:
  Fix pbxt test suite failures:
  - Update EXPLAIN results after table elimination
mysql-test/suite/pbxt/r/union.result:
  Fix pbxt test suite failures:
  - Update EXPLAIN results after table elimination
mysql-test/suite/pbxt/t/connect.test:
  Fix pbxt test suite failures:
  - For some reason, mysqltest logs "connect" command differently when PBXT
    is the default storage engine. This is probably a bug in mysqltest which
    we can't be bothered to investigate at the moment, so add --replace