SHOW PROFILES shows how much time MySQL spends in various phases of query execution, but it isn’t a full-featured profile. By that… set (0.18 sec) The query consumed 0.18 seconds. Where did the time go? mysql> SHOW PROFILE FOR QUERY 1; +———————-+———-+ | Status | Duration | +———————-+———-+ | starting…
Post: Profiling MySQL stored routines
January 19, 2009 By 3 Comments
… 1 row in set (0.00 sec) mysql> show profiles; +———-+————+————————————————————-+ | Query_ID | Duration | Query | +———-+————+————————————————————-+ | 1 | 0.00005100 | SELECT CURTIME() into time…
Post: Identifying the load with the help of pt-query-digest and Percona Server
December 29, 2011 By 3 Comments
Overview Profiling, analyzing and then fixing queries is likely the most oft-repeated part of a job … points you need to attack the right query in the right way. But vanilla MySQL does have its limitations, it reports only… analyze next part of the output produced by pt-query-digest. # Profile # Rank Query ID Response time Calls R/Call Apdx V/M…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…MySQL manual, … profilingblogpercona.commanual profiling_history_sizeblogpercona…query_cache_limitblogpercona.commanual query_cache_min_res_unitblogpercona.commanual query_cache_sizeblogpercona.commanual query_cache_typeblogpercona.commanual query_cache_wlock_invalidateblogpercona.commanual query…
Post: Using flow control functions for performance monitoring queries
May 24, 2008 By 12 Comments
… like IF or CASE used in MySQL Queries as they are often abused used to create queries which are poorly readable as well as can hardly be optimized well by MySQL Optimizer. One way… track types of pages because they often have different performance profile. mysql> select count(*) cnt, avg(wtime) avw, sum(if(wtime>0…
Post: Troubleshooting MySQL Upgrade Performance Regressions
February 15, 2012 By Leave a Comment
… the query which performs differently between MySQL Server versions you should: Check Query Plan Run EXPLAIN to see if plans for the query are… can also check SHOW PROFILE to see where differences are. Running query in the loop and getting o_profile sample can also be a good idea. If you found query is executing…
Post: How to Identify Bad Queries in MySQL
January 10, 2011 By 16 Comments
… the system by grouping queries into classes and summing the execution time together. Then it prints out a profile of the classes… the timestamp when the query executed, not merely the duration the query executed for, which has been available in MySQL for years. This is necessary for determining whether a group of queries completed…
Post: MySQL versions shootout
October 10, 2011 By 6 Comments
… question: MySQL 4.1 MySQL 5.0 MySQL 5.1 (with built-in InnoDB) MySQL 5.1 with InnoDB-plugin MySQL 5.5 MySQL 5.6… overhead. Profiling MySQL 5.0 vs MySQL 4.1 couple years ago, I have seen biggest performance hit comes from query parser. In MySQL 5… (more is better) threads MySQL 4.1 MySQL 5.0 MySQL 5.1 MySQL 5.1+InnoDB-plugin MySQL 5.5 MySQL 5.6.2 1…
Post: MySQL Configuration Wizard Updated
January 26, 2012 By 5 Comments
…out the first iteration of the account and profile features. Now you get a homepage with your…options to prevent common problems MySQL users run into because of too-permissive MySQL behaviors. These are the… a visual EXPLAIN tool, a configuration advisor, a query analysis tool, a way to register a …
Post: Improved InnoDB fast index creation
November 6, 2011 By 4 Comments
… used: mysql> SET profiling=1; Query OK, 0 rows affected (0.00 sec) mysql> ALTER TABLE t ADD COLUMN v VARCHAR(1); Query OK, 4194304… v VARCHAR(2); Query OK, 4194304 rows affected (36.07 sec) Records: 4194304 Duplicates: 0 Warnings: 0 mysql> SHOW PROFILE; +——————————+———–+ | Status | Duration | +——————————+———–+ | starting…
