…TRANSACTION; transaction1> SELECT * FROM t WHERE i > 20 FOR UPDATE; +——+ | i | +——+ | 21 | | 25 | | 30 | +——+ …(s), undo log entries 1 MySQL thread id 3, OS thread handle 0x7f84a78ba700, query id 163…://dev.mysql.com/doc/refman/5.1/en/innodb-locks-set.html. Conclusion MySQL uses REPEATABLE…
Post: Microslow patch for 5.1.20
July 18, 2007 By 3 Comments
… logging with –slow-query-log parameter. MySQL 5.1 has this nice feature which allows you to redirect query log (it’s actually called general log now) and slow log… output for your logs to the plain old-fashioned files. In MySQL 5.1 it’s done by setting –log-slow-queries=slow.log and –log-output=FILE…
Post: Percona Server 5.5.14-20.5
August 17, 2011 By 4 Comments
…MySQL 5.5.14, including all the bug fixes in it, Percona Server 5.5.14-20.5 is now the current stable release in the 5.5…transaction log…MySQL 5.0 or 5.1 prior to version 5.1.24. A fix for a MySQL bug (#27877) introduced an incompatible change in collations in MySQL 5.1…MySQL (Alexey Kopytov). Querying…
Post: Scaling problems still exist in MySQL 5.5 and Percona Server 5.5
May 20, 2011 By 11 Comments
MySQL 5.5 and Percona Server 5.5 do not solve all scalability problems even …in the application by aggregating query log with mk-query-digest. When I filtered out only queries of this pattern and … I have compared Percona Server 5.1.56-12.7 and Percona Server 5.5.11-20.2 with former being configured …
Post: Identifying the load with the help of pt-query-digest and Percona Server
December 29, 2011 By 3 Comments
… using the vanilla MySQL server, you would see an entry like this in the slow query log: # Time: 111229…:32 2011 # Hostname: somehost.net # Files: slow-query.log.1 # Overall: 20.08k total, 167 unique, 16.04 QPS, 0… SELECT wp_options # 8 0x4C16888631FD8EDB 0.1160 1.4% 5 0.0232 1.00 0.00 SELECT film # 9…
Post: Modeling MySQL Capacity by Measuring Resource Consumptions
March 8, 2011 By 1 Comment
…log/mysql# cat /proc/19018/stat 19018 (mysqld) S 1 19018 19018 0 -1 4202752 198731 0 0 0 347 5303 0 0 20 0 20…query logging and log_slow_verbosity=full you can also get great amount of related data from mk-query-digest report: # Overall: 1…sent 8.77G 11 55.41M 5.15k 3.88k 258.55k 1.46k # Merge passes …
Post: Percona Server 5.5.10 (Release Candidate)
April 4, 2011 By 4 Comments
… 5.5.10-20.1 is now available for download. This is a release candidate for the Percona Server 5.5 series. In addition to MySQL 5.5… to slow_query_log_timestamp_always. (Oleg Tsarev) Old system variable slow_query_log_microseconds_timestamp was renamed to slow_query_log_timestamp_precision. (…
Post: High-Performance Click Analysis with MySQL
December 22, 2008 By 13 Comments
…your data is coming from some Apache log or similar source. Write a …. It’s the classic 80-20 rule. Maybe 80% of your …work by either using MySQL 5.1‘s row-based replication, or in MySQL 5.0 and earlier, … than MySQL is, especially for more complex queries. Percona is not tied to MySQL, although …
Post: Guess what?! Microsecond slow query timing finally available in MySQL!
August 29, 2007 By 5 Comments
… Microslow patch for 5.1.21, because the previous one I wrote for 5.1.20 failed to apply correctly on the new MySQL release. Imagine… out that MySQL incorporated the patch to their release. So it’s a built-in feature now in the 5.1 line. So far I noticed one addition to my code which is logging the microtime statistics into TABLE type log storage…
Comment: Guess what?! Microsecond slow query timing finally available in MySQL!
August 31, 2007 By 5 Comments
… MySQL – was data type extended or the column changed to different type ? Also was only pure timing support added to the MySQL 5.1.20 or were other features you’ve implemented, such as logging slow queries from replication thread as well and having rows examined and rows updated in the slow query log added as…
