…_memory and innodb_descriptors_memory status variables in the Extended Show Engine InnoDB Status to improve InnoDB memory usage diagnostics. Bugs… the MySQL 5.6 version, which removed MyISAM internal temporary table mutex contention. Bug fixed #1179978. Release notes for Percona Server for MySQL 5…
Post: MySQL Query Patterns, Optimized - Webinar questions followup
June 3, 2013 By 2 Comments
… are other drawbacks to using temporary tables in this way, for example when using replication, a temporary table could vanish if the slave restarts… temporary table to count the movies per production year for each kind_id. It was more efficient in this case to force MySQL… were trying to determine the last episode of each TV show. Couldn’t you have used a SUBQUERY to fetch and…
Post: Percona XtraDB Cluster 5.5.30-23.7.4 for MySQL now available
April 17, 2013 By 2 Comments
… available for download from our repositories. Benchmark showing the impact of memory allocators on MySQL performance can be found in this blogpost… when DROP TEMPORARY TABLE statement was used, but it will still replicate in case DROP TABLE statement is used on a temporary table. Bug fixed…
Post: Webinar: MySQL 5.6 Performance Schema
May 13, 2013 By 5 Comments
….m. Pacific, I’ll be leading a Webinar titled, “Using MySQL 5.6 Performance Schema to Troubleshoot Typical Workload Bottlenecks.” In… that have been added in MySQL 5.6, go over the configuration and spend most time showing how you can use the… of focus include: Bottlenecks with Disk IO Problems with excessive temporary tables and external sorts Excessive internal mutex contention Slow queries due…
Post: SHOW OPEN TABLES - what is in your table cache
December 14, 2008 By 3 Comments
…temporary tables in the table-cache, showing each of them only once (even if table is opened more than ones) In_use show…
Post: Can MySQL temporary tables be made safe for statement-based replication?
May 26, 2008 By 8 Comments
… tables. Thus, I claimed, there’s no alternative but to eliminate temporary tables. This problem may not exist for row-based replication in MySQL… some changes, create a temporary table with ENGINE=InnoDB, and the InnoDB transaction ID does not change in SHOW INNODB STATUS. The statements…
Post: How much overhead is caused by on disk temporary tables
August 16, 2007 By 26 Comments
… not how it happens in practice. mysql> show global status like “key%”; +————————+———+ | Variable_name | Value | …temporary tables can be 10-100 times faster than disk based MyISAM tables Hopefully MySQL will implement support of dynamic rows for MEMORY tables…
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 5 Comments
…temporary tables (both in memory and not): mysql> select * from information_schema.global_temporary_tables \G *************************** 1. row *************************** SESSION_ID: 7234 TABLE_SCHEMA: test TABLE… do as it is least intrusive. Run SHOW ENGINE INNODB STATUS and look for memory …
Post: On Character Sets and Disappearing Tables
June 21, 2012 By 1 Comment
…1146 (42S02): Table ‘oops4.dos2′ doesn’t exist (root@localhost) [oops4]> show tables; +—————–+ | Tables_in_oops4 | +—————–+ | dos1 | |… actual filename of the temporary table rather than the temporary table name that was … of an inconsistency present when MySQL won’t allow us to …
Post: How to convert MySQL's SHOW PROFILES into a real profile
February 20, 2012 By 12 Comments
… 0.18 seconds. Where did the time go? mysql> SHOW PROFILE FOR QUERY 1; +———————-+———-+ | Status | Duration | +———————-+———-+ | starting | 0.000032 | … was spent working with temporary tables. But there’s something still missing: it doesn’t show lost time (the …
