…16384 INDEX_LENGTH: 0 CREATE_TIME: NULL UPDATE_TIME: NULL *************************** 2. row *************************** SESSION_ID: …memory leaks like valgrind are too slow to run in production. So the… where your MySQL Support contract can be handy. Conclusion Understanding where MySQL can allocate…
Comment: Percona Toolkit 2.1 with New Online Schema Change Tool
April 22, 2012 By 9 Comments
… your help and information. I just made the MySQL, apache2 and php updates available to Debian Squeeze avalable on DotDeb.org, and… if MySQL 5.5 has been getting much slower (in terms of qps) with the last two or three minor updates since… across the board to everyone? Have some updates made to INNOdb tables really slowed down mySQL as measured by qps, in the last…
Post: Scaling problems still exist in MySQL 5.5 and Percona Server 5.5
May 20, 2011 By 11 Comments
…,btr_search_build_page_hash_index,btr_search_info_update_slow,btr_search_info_update,btr_cur_search_to_nth_level,btr_p…,sub_select,do_select,JOIN::exec,mysql_sel ect,handle_select,execute_sqlcom_select,mysql_execute_command,mysql_parse,dispatch_command,do_command…,btr_search_build_page_hash_index,btr_search_info_update_slow,btr_search_info_update,btr_cur_search_to_nth_level,btr_p…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…amazing MySQL manual, especially the option and …Slow_launch_threadsblogpercona.commanual slow_launch_timeblogpercona.commanual Slow_queriesblogpercona.commanual slow_query_logblogpercona.commanual slow….commanual unique_checksblogpercona.commanual updatable_views_with_limitblogpercona.commanual …
Post: Figuring out what limits MySQL Replication
March 7, 2007 By Leave a Comment
… limiting MySQL Replication speed. My first idea was to check it based on slow query log, happily the server was running MySQL with slow query log with microsecond resolution so I could check exactly which update… to mysqlsla which I remembered parses all kinds of MySQL Logs. Too bad MySQL Binary log is the only one which it…
Post: Reasons for MySQL Replication Lag
July 29, 2011 By 6 Comments
… as increasing buffer pool size could cause performance problems. MySQL Restart MySQL Restarts may include recovery time but what is the most… with mk-query-digest (Percona Server marks Slave Thread in slow query log so it is easy to filter out events… involved. In could be even system which queries mysql. I’ve seen monitoring updates which would add excessively expensive and frequent query…
Post: When Does InnoDB Update Table Statistics? (And When It Can Bite)
October 6, 2011 By 5 Comments
… suddenly show up on slow query log until InnoDB again updates the statistics. But when does InnoDB perform the updates aside from the… has been modified, whichever comes first. ./row/row0mysql.c:row_update_statistics_if_needed If you or an application constantly executes… to update all the tables’ statistics. Luckily, this can be controlled with Percona Server with the variable innodb_stats_auto_update (from MySQL…
Post: Solving INFORMATION_SCHEMA slowness
December 23, 2011 By 16 Comments
… things like it. Besides being just slow accessing information_schema can often impact …_metadata=0 which will prevent statistic update when you query information_schema. Most …| 130 | 2856365892 | +———-+——————+ 1 row in set (1.08 sec) mysql> set global innodb_stats_on_metadata=0;…
Post: MySQL 4 to MySQL 5 Upgrade performance regressions
June 6, 2007 By 8 Comments
… am extremely unhappy how MySQL handled this problem. While working for MySQL we spotted this problem early in MySQL 5.0 release cycle…. If you have update prevailing load you would see very strange behavior on 5.0 of MySQL being slow but few queries being… should stay on MySQL 4.1 until MySQL has taken it away from you as already happened with MySQL 4.0. MySQL 5.0…
Post: Troubleshooting MySQL Upgrade Performance Regressions
February 15, 2012 By Leave a Comment
… system. Rather often people panic and what thought to be slow down with version upgrade is rather system warming up. You… it without side load. Setting up 2 MySQL Servers side by side (for example with MySQL Sandbox) can especially be helpful. Once… may be wrong plan from optimizer standpoint and updating stats may cause old MySQL Version to get slower plan instead of new…
