… points you need to attack the right query in the right way. But vanilla MySQL does have its limitations, it reports only… have enabled slow query logging and set a low enough value for long_query_time. We normally use a value of long_query_time=0, because if you set it to some other value say 0.1 seconds, it will miss all queries…
Post: Identifying the load with the help of pt-query-digest and Percona Server
December 29, 2011 By 3 Comments
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…am constantly referring to the amazing MySQL manual, especially the option and variable reference table. But just…_tcblogpercona.commanual log_tc_sizeblogpercona.commanual log_warningsblogpercona.commanual long_query_timeblogpercona.commanual low_priority_updatesblogpercona.commanual lower_case_file_…
Post: Common MySQL traps webinar questions followup
January 17, 2013 By 1 Comment
… slow query logging (with long_query_time = 0) for some time during peak load. Then you can use pt-query-digest to analyze the queries and have a report of the queries that are causing the most… SQL query writing and wanted to learn MySQL administration suggest any book or practices. Of course I’m biased but High Performance MySQL…
Post: MySQL Slow query log in the table
May 31, 2007 By 1 Comment
As of MySQL 5.1 get MySQL slow query log logged in mysql.slow_log table instead of the file as you had … in MySQL is well though of in regards to avoiding trouble. For example you can’t ALTER log table while query is… table to MyISAM, disable concurrent inserts and run long reporting query on the log file query execution is still proceeds. I have not…
Post: Load management Techniques for MySQL
May 6, 2012 By 3 Comments
One of the very frequent cases with performance problems with MySQL is what they happen every so often or certain times… need to know it is not MySQL problem, might be even not problem with your MySQL configuration, queries and hardware, even though fixing… too much in this case throttling by having relatively short queries and introducing “sleeps” between them can be a good idea…
Post: How to debug long-running transactions in MySQL
March 8, 2011 By 6 Comments
… figure out what the long-running transaction is doing. The most obvious is if it’s a long-running query. If that’s the case, then you’ll see the query in the processlist, and… a while, use mk-query-digest to convert this into a query log, and examine the log. In MySQL 5.1 and newer…
Post: Implications of Metadata Locking Changes in MySQL 5.5
February 1, 2013 By 9 Comments
… metadata locks on the table it has accessed for as long as the transaction is open. Since an open transaction retains… bug: http://bugs.mysql.com/bug.php?id=67647 Metadata locking behaves differently for queries that are serviced from the Query Cache, let… Table Cache, any query to a table that has a DDL operation waiting, will block. Why? Because MySQL sees that the old…
Post: Get Me Some Query Logs!
November 22, 2012 By 14 Comments
… slow_query_log=1 Discovering slow_query_log_file=mysql-slow.log Discovering long_query_time=60.000000 Setting long_query_time=0 Setting slow_query_log_file=mysql-slow.log-full-20121122112413 Setting slow_query…
Post: High-Performance Click Analysis with MySQL
December 22, 2008 By 13 Comments
… the chance to parallelize. As you know, MySQL doesn’t do intra-query parallelization, so ETL jobs written to rely on… you need unless you’re okay with long queries that read a lot of rows — MySQL can’t handle too many of those… out-of-the-box than MySQL is, especially for more complex queries. Percona is not tied to MySQL, although we’re most famous…
Post: Slow Query Log analyzes tools
September 6, 2006 By 84 Comments
… specify slow query time in microseconds rather than seconds and allows you to log all queries in slow query log by setting long_query_time=0 This patch is adapted version of patch by Georg Richter which was made to run with recent MySQL… for all your queries with long_query_time=0 so if serious portion of you load comes from very simple queries you would not…
