Add the I_S.GLOBAL_STATUS counter innodb_instant_alter_column

mysql-test/suite/innodb/t/instant_alter.test

@@ -18,6 +18,10 @@ SET time_zone='+03:00';
 SET @saved_frequency= @@GLOBAL.innodb_purge_rseg_truncate_frequency;
 SET GLOBAL innodb_purge_rseg_truncate_frequency=1;
 
+SET @old_instant=
+(SELECT variable_value FROM information_schema.global_status
+WHERE variable_name = 'innodb_instant_alter_column');
+
 let $format= 3;
 while ($format) {
 let $engine= `SELECT CONCAT('ENGINE=InnoDB ROW_FORMAT=',CASE $format
@@ -33,7 +37,6 @@ eval CREATE TABLE t1
 INSERT INTO t1 (id, c2) values(1,1);
 SELECT * FROM t1;
 
-SET GLOBAL innodb_monitor_enable = module_ddl;
 --enable_info
 ALTER TABLE t1 ADD COLUMN (
   d1 INT, d2 INT UNSIGNED DEFAULT 10, d3 VARCHAR(20) NOT NULL DEFAULT 'abcde',
@@ -252,9 +255,7 @@ DROP TABLE t1,t2,t3,big;
 dec $format;
 }
 disconnect analyze;
-SET GLOBAL innodb_monitor_disable = module_ddl;
---disable_warnings
-SET GLOBAL innodb_monitor_enable  = default;
-SET GLOBAL innodb_monitor_disable = default;
---enable_warnings
+SELECT variable_value-@old_instant instants
+FROM information_schema.global_status
+WHERE variable_name = 'innodb_instant_alter_column';
 SET GLOBAL innodb_purge_rseg_truncate_frequency= @saved_frequency;

storage/innobase/handler/ha_innodb.cc

@@ -1100,6 +1100,9 @@ static SHOW_VAR innodb_status_variables[]= {
   {"defragment_count",
   (char*) &export_vars.innodb_defragment_count, SHOW_LONG},
 
+  {"instant_alter_column",
+  (char*) &export_vars.innodb_instant_alter_column, SHOW_LONG},
+
   /* Online alter table status variables */
   {"onlineddl_rowlog_rows",
   (char*) &export_vars.innodb_onlineddl_rowlog_rows, SHOW_LONG},

storage/innobase/handler/handler0alter.cc

@@ -50,6 +50,7 @@ Smart ALTER TABLE
 #include "trx0roll.h"
 #include "handler0alter.h"
 #include "srv0mon.h"
+#include "srv0srv.h"
 #include "fts0priv.h"
 #include "fts0plugin.h"
 #include "pars0pars.h"
@@ -304,6 +305,7 @@ struct ha_innobase_inplace_ctx : public inplace_alter_handler_ctx
 		}
 
 		new_table = old_table;
+		export_vars.innodb_instant_alter_column++;
 	}
 
 	/** @return whether this is instant ALTER TABLE */

storage/innobase/include/srv0srv.h

@@ -1007,6 +1007,9 @@ struct export_var_t{
 	ulint innodb_defragment_count;		/*!< Number of defragment
 						operations*/
 
+	/** Number of instant ALTER TABLE operations that affect columns */
+	ulong innodb_instant_alter_column;
+
 	ulint innodb_onlineddl_rowlog_rows;	/*!< Online alter rows */
 	ulint innodb_onlineddl_rowlog_pct_used; /*!< Online alter percentage
 						of used row log buffer */