Merge a change from MySQL AB:

ChangeSet@1.2409.1.83  2007-03-06 10:36:15-07:00  tsmith@hindu.god
Bug #26598: Create variable to allow turning off of statistic gathering
on metadata commands

Add innodb_stats_on_metadata option, which enables gathering
index statistics when processing metadata commands such as
SHOW TABLE STATUS.  Default behavior of the server does not
change (this option is enabled by default).

handler/ha_innodb.cc

@@ -129,6 +129,7 @@ my_bool	innobase_file_per_table			= FALSE;
 my_bool innobase_locks_unsafe_for_binlog	= FALSE;
 my_bool innobase_rollback_on_timeout		= FALSE;
 my_bool innobase_create_status_file		= FALSE;
+my_bool innobase_stats_on_metadata		= TRUE;
 
 static char *internal_innobase_data_file_path	= NULL;
 
@@ -1651,6 +1652,8 @@ innobase_init(void *p)
 	srv_max_n_open_files = (ulint) innobase_open_files;
 	srv_innodb_status = (ibool) innobase_create_status_file;
 
+	srv_stats_on_metadata = (ibool) innobase_stats_on_metadata;
+
 	srv_print_verbose_log = mysqld_embedded ? 0 : 1;
 
 	/* Store the default charset-collation number of this MySQL
@@ -5563,15 +5566,17 @@ ha_innobase::info(
 	ib_table = prebuilt->table;
 
 	if (flag & HA_STATUS_TIME) {
-		/* In sql_show we call with this flag: update then statistics
-		so that they are up-to-date */
+		if (srv_stats_on_metadata) {
+			/* In sql_show we call with this flag: update then statistics
+			so that they are up-to-date */
 
-		prebuilt->trx->op_info = (char*)"updating table statistics";
+			prebuilt->trx->op_info = (char*)"updating table statistics";
 
-		dict_update_statistics(ib_table);
+			dict_update_statistics(ib_table);
 
-		prebuilt->trx->op_info = (char*)
-					  "returning various info to MySQL";
+			prebuilt->trx->op_info = (char*)
+						  "returning various info to MySQL";
+		}
 
 		my_snprintf(path, sizeof(path), "%s/%s%s",
 				mysql_data_home, ib_table->name, reg_ext);

handler/ha_innodb.h

@@ -213,7 +213,8 @@ extern my_bool innobase_log_archive,
 	innobase_use_native_aio,
 	innobase_file_per_table, innobase_locks_unsafe_for_binlog,
 	innobase_rollback_on_timeout,
-	innobase_create_status_file;
+	innobase_create_status_file,
+	innobase_stats_on_metadata;
 extern "C" {
 extern ulong srv_max_buf_pool_modified_pct;
 extern ulong srv_max_purge_lag;

include/srv0srv.h

@@ -124,6 +124,8 @@ extern ulint	srv_fast_shutdown;	 /* If this is 1, do not do a
 					 transactions). */
 extern ibool	srv_innodb_status;
 
+extern ibool	srv_stats_on_metadata;
+
 extern ibool	srv_use_doublewrite_buf;
 extern ibool	srv_use_checksums;
 

srv/srv0srv.c

@@ -317,6 +317,8 @@ ulint	srv_fast_shutdown	= 0;
 /* Generate a innodb_status.<pid> file */
 ibool	srv_innodb_status	= FALSE;
 
+ibool	srv_stats_on_metadata	= TRUE;
+
 ibool	srv_use_doublewrite_buf	= TRUE;
 ibool	srv_use_checksums = TRUE;