Noob question: Isn’t slow_query_log also a session variable? In our environment we have apps that stay connected to … at a time. If you set global slow_query_log=0 won’t active sessions ignore the change? Is there some way…
Post: Announcing Percona XtraDB Cluster 5.5.27-23.6
September 7, 2012 By Leave a Comment
… MB) and the minimum index record size. By adding the session variable innodb_merge_sort_block_size, block size that is used… Modifiers have been added to allow access control to system variables. New table INNODB_UNDO_LOGS has been added to allow… undo segment. This information is “live” and calculated for each query of the table. Percona XtraDB Cluster now has improved “clustercheck…
Post: Announcing Percona Server 5.5.27-28.0
August 23, 2012 By 5 Comments
… MB) and the minimum index record size. By adding the session variable innodb_merge_sort_block_size block size that is used… Modifiers have been added to allow access control to system variables. New table INNODB_UNDO_LOGS has been added to allow…. Bug fixed #882653 (Stewart Smith). Fixed the malformed CHANGE MASTER query in the output of mysqldump with –include-master-host-port…
Post: MySQL: Followup on UNION for query optimization, Query profiling
August 14, 2006 By 14 Comments
…profile queries to see what exactly happens during query execution -… mysql> show status like “Handler%”; +—————————-+——-+ | Variable_name | Value | +—————————-+——-+ | Handler_commit | 0 | | Handler_delete… now will show per session counter increments and to…
Post: Investigating MySQL Replication Latency in Percona XtraDB Cluster
March 3, 2013 By 13 Comments
… synchronous replication behavior: mysql> set global wsrep_causal_reads=1; Query OK, 0 rows affected (0.00 sec) When this option… the read. The great thing is wsrep_causal_reads is session variables so you can mix different applications on the same cluster… sec) Rows matched: 1000000 Changed: 1000000 Warnings: 0 Running this query on the DPE1 box I’m getting following result: … Result…
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 5 Comments
… There is no comparable variables of how many user variables are allocated (and how… MEMORY tables which are allocated for query execution, which size can be …_schema.global_temporary_tables \G *************************** 1. row *************************** SESSION_ID: 7234 TABLE_SCHEMA: test TABLE_…
Post: Test Drive of Solid
September 22, 2006 By 5 Comments
… | Solid | +—-+——-+ 1 row in set (0.00 sec) Session 2: mysql> begin; Query OK, 0 rows affected (0.00 sec) mysql> select…: Query OK, 1 row affected (9.65 sec) Rows matched: 1 Changed: 1 Warnings: 0 Test 2: SELECT FOR UPDATE (second session is not blocked): Session1: mysql> begin; Query OK, 0 rows affected (0.00 sec…
Post: Implications of Metadata Locking Changes in MySQL 5.5
February 1, 2013 By 9 Comments
…) default ‘dummy_text’; Query OK, 2 rows affected (59.80 sec) session10 > show status like ‘Open%tables’; +—————+——-+ | Variable_name | Value | +—————+——-+ | …for example in web applications its typical to see a “sessions” table that is accessed on every request, then care…
Post: Percona Server 5.5.8 Beta Release
February 16, 2011 By 16 Comments
…) Old variable innodb_flush_log_at_trx_commit_session was deleted. Bug fixed: #635399. (Yasufumi Kinoshita) Old variable use_global_long_query_time was deleted. (Oleg Tsarev) Bug fixed: #692415. Old variable…
Post: InnoDB's gap locks
March 27, 2012 By 15 Comments
… lock, when you run the same query twice, you get the same result, regardless other session modifications on that table. This makes… t VALUES(31); Query OK, 1 row affected (0.00 sec) After running the delete statement on the first session, not only… options is that the second one is a global variable that affects all sessions and needs a server restart to change its…
