SHOW PROFILES shows how much time MySQL spends in various phases of query execution, but it isn’t a full-featured profile. By… profile the “nicer_but_slower_film_list” included with the Sakila sample database to demonstrate: mysql> SET profiling=1; mysql> pager cat > /dev/null mysql… query consumed 0.18 seconds. Where did the time go? mysql> SHOW PROFILE FOR QUERY 1; +———————-+———-+ | Status | Duration | +———————-+———-+ | starting | 0.000032 | | checking…
Post: Profiling MySQL stored routines
January 19, 2009 By 3 Comments
…’s SHOW PROFILE patch – which is included in all Community tree based Percona MySQL builds since it is part of MySQL community version… show you how this works: mysql> set profiling=1; Query OK, 0 rows affected (0.00 sec) mysql> SELECT whatstheweatherlike(3); +———————————————————–+ | whatstheweatherlike(3…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
… referring to the amazing MySQL manual, especially the option and variable reference table. …_stmt_countblogpercona.commanual print_defaultsblogpercona.commanual profilingblogpercona.commanual profiling_history_sizeblogpercona.commanual protocol_versionblogpercona.commanual proxy_userblogpercona…
Post: Troubleshooting MySQL Upgrade Performance Regressions
February 15, 2012 By Leave a Comment
… it without side load. Setting up 2 MySQL Servers side by side (for example with MySQL Sandbox) can especially be helpful. Once… whenever internal operation is different, you 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…
Post: Three ways that the poor man's profiler can hurt MySQL
December 2, 2011 By 19 Comments
… technique of using GDB as a profiler has become a key tool in helping us analyze MySQL when customers are having trouble… they can be. Of course, I’m really waiting for MySQL 5.6 and the improved Performance Schema that will be…
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…. 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: Getting MySQL Core file on Linux
August 26, 2011 By 1 Comment
… dumped by setuid processes (and MySQL Server is most commonly ran changing user from “root” to “mysql“). Before you embark on enabling…/sbin/mysqld[0x516a61] The manual page at http://dev.mysql.com/doc/mysql/en/crashing.html contains information that should help you… if you expect to do any MySQL profiling or dealing with crashes. It does not slow MySQL performance yet it is very helpful…
Post: More on MySQL Error Messages
April 6, 2011 By 9 Comments
… some extra files, which do not belong to MySQL in database directory. MySQL will only remove files it knows about such as…. Another enjoyable error message: “Can’t find messagefile ‘/usr/share/mysql/english/errmsg.sys” Everything is good and clear right ? Nope… parent=32631 profile=”/usr/sbin/mysqld” requested_mask=”r::” denied_mask=”r::” fsuid=0 ouid=0 name=”/usr/share/mysql/english/errmsg…
Post: MySQL Configuration Wizard Updated
January 26, 2012 By 5 Comments
…’ve rolled out the first iteration of the account and profile features. Now you get a homepage with your configuration files… sanity/safety options to prevent common problems MySQL users run into because of too-permissive MySQL behaviors. These are the kinds of… that Drizzle fixes — and should be fixed by default in MySQL — but never will be because they might break applications that…
Post: How to Identify Bad Queries in MySQL
January 10, 2011 By 16 Comments
… summing the execution time together. Then it prints out a profile of the classes, so you can see which ones contribute… duration the query executed for, which has been available in MySQL for years. This is necessary for determining whether a group… a cluster. One-second granularity (what you get in standard MySQL) might be enough precision for finding some cases of queries…
