…query temporary tables too: mysql> select sum(data_length+index_length) from information_schema.global_temporary_tables where engine=’memory’; +——————————-+ | sum(data_length+index…check which sessions have created which temporary tables (both in memory and not): mysql…tools…
Post: Slow Query Log analyzes tools
September 6, 2006 By 83 Comments
…queries which do not use indexes even if they take less time (–log-queries-not-using-indexes) Slow query log is great to spot really slow queries…queries. Once you have created full log – parse it and check queries using…
Post: MySQL extensions for hosting
April 24, 2008 By 11 Comments
…check what data or which index are the most active or which are not being used…not uncommon someone uploads a really badly designed application, which runs queries not using indexes…mysql> SHOW INDEX_STATISTICS LIKE ‘hosting2%’; +——————————————–+———–+ | Index…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
… are the lowest common denominator. We often use tools to gather a lot of the data … including checking for default users in the mysql.* tables, running mk-duplicate-key-checker to find redundant indexes, … shortcut effort if it’s not useful, e.g. skipping analysis for a query the client’s developers …
Post: How to recover deleted rows from an InnoDB Tablespace
February 20, 2012 By 3 Comments
…INDEX_ID | NAME | +———-+———+ | 26 | PRIMARY | | 27 | emp_no | +———-+———+ B) InnoDB Table Monitor The index information can also be taken directly from MySQL using…Check…Query OK, 3 rows affected (0.01 sec) Records: 3 Deleted: 0 Skipped: 0 Warnings: 0 mysql…
Post: MySQL Slow query log in the table
May 31, 2007 By Leave a Comment
…use this feature as it is incompatible with our slow query analyses patch and tools Fixing this is not … have indexes would be quite handy I also should tell log table implementation in MySQL is … long reporting query on the log file query execution is still proceeds. I have not checked if concurrent …
Post: ANALYZE: MyISAM vs Innodb
September 3, 2008 By 9 Comments
…queries” (using constants for index accesses) will not use index cardinality data at all but will estimate number of rows during query…check how stats change for MyISAM if we change the stats computation method: mysql> set myisam_stats_method=’nulls_equal’; Query…
Post: How (not) to find unused indexes
October 16, 2009 By 2 Comments
… only sending query 1 to MySQL it’s actually a pretty good index! It’s not always like…not. If you are not running a patched server, then the alternative is to either use a proxy that checks…subtract the indexes that were mentioned from all indexes known. There’s an old tool called mysqlidxchx …
Post: Database problems in MySQL/PHP Applications
August 11, 2006 By 12 Comments
…checks and query rewriting. You also can use pretty much direct path to mysqli extension to performance critical queries…Not using Join. This is typical error. On other hand in MySQL you might be better of using several queries…not expect it soon. Use Indexes This item was not…
Post: Shard-Query EC2 images available
May 11, 2011 By 2 Comments
…Query. Each image comes pre-loaded with the data used in the previous Shard-Query…indexes) # du -sh * 203M ibdata1 128M ib_logfile0 128M ib_logfile1 988K mysql…Index_length: 539279360 Data_free: 4194304 Auto_increment: NULL Create_time: 2011-05-10 04:26:14 Update_time: NULL Check…tools…
