As part of work on “High Performance MySQL, 3rd edition”, Baron asked me to compare different MySQL version in some simple benchmark, but on decent hardware. So why not.
Preprocessing Data
August 8, 2011 By 3 Comments
There are many ways of improving response times for users. There are some people that spend a lot of time, energy and money on trying to have the application respond as fast as possible at the time when the users made the request. Those people may miss out on an opportunity to do some or [...]
Using Flexviews – part two, change data capture
March 25, 2011 By 26 Comments
In my previous post I introduced materialized view concepts. This post begins with an introduction to change data capture technology and describes some of the ways in which it can be leveraged for your benefit. This is followed by a description of FlexCDC, the change data capture tool included with Flexviews. It continues with an [...]
The story of one MySQL Upgrade
October 8, 2010 By 8 Comments
I recently worked on upgrading MySQL from one of very early MySQL 5.0 versions to Percona Server 5.1. This was a classical upgrade scenario which can cause surprises. Master and few slaves need to be upgraded. It is a shared database used by tons of applications written by many people over more than 5 years [...]
Debugging problems with row based replication
May 6, 2010 By 12 Comments
MySQL 5.1 introduces row based binary logging. In fact, the default binary logging format in GA versions of MySQL 5.1 is ‘MIXED’ STATEMENT*; The binlog_format variable can still be changed per sessions which means it is possible that some of your binary log entries will be written in a row-based fashion instead of the [...]
Crashes while using MyISAM with multiple key caches
July 18, 2009 By Leave a Comment
Over last couple of years I have ran into random MySQL crashes in production when multiple key caches were used. Unfortunately this never was frequent or critical enough issue so I could spend time creating repeatable test case and search of the bug in the MySQL database did not find anything. Recently we had this [...]
The feature I love in TokuDB
June 11, 2009 By 4 Comments
Playing with TokuDB updates I noticed in SHOW PROCESSLIST unsual for MySQL State.
1 2 3 4 5 6 7 8 9 10 11 12 | mysql> show processlist; +----+------+-----------+--------+---------+------+---------------------------+-----------------------------+ | Id | User | Host | db | Command | Time | State | Info | +----+------+-----------+--------+---------+------+---------------------------+-----------------------------+ | 3 | root | localhost | sbtest | Query | 30 | Updated about 764000 rows | update sbtest set email=zip | ... mysql> show processlist; +----+------+-----------+--------+---------+------+----------------------------+-----------------------------+ | Id | User | Host | db | Command | Time | State | Info | +----+------+-----------+--------+---------+------+----------------------------+-----------------------------+ | 3 | root | localhost | sbtest | Query | 79 | Updated about 1900000 rows | update sbtest set email=zip | ... |
(Do not look in stupid UPDATE query, it’s just for testing ) So looking in SHOW PROCESSLIST you can see progress of query execution. I would want to see it in standard MySQL and InnoDB more than all these triggers and [...]
How much memory can MySQL use in the worst case?
February 12, 2009 By 17 Comments
I vaguely recall a couple of blog posts recently asking something like “what’s the formula to compute mysqld’s worst-case maximum memory usage?” Various formulas are in wide use, but none of them is fully correct. Here’s why: you can’t write an equation for it.
Why audit logging with triggers in MySQL is bad for replication
September 29, 2008 By 10 Comments
Recently I was tasked with investigating slippage between master and slave in a standard replication setup. The client was using Maatkit’s mk-table-checksum to check his slave data was indeed a fair copy of that of the master.
Is it query which needs to be optimized ?
March 6, 2007 By 9 Comments
Last few days I had a lot of a lot of questions at MySQL Performance Forum as well as from our customers regarding query optimization… which had one thing in common – It is not query which needed to be optimized. Way too frequently people design schema first and then think how the queries they [...]
