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 [...]
What to do with MySQL Full Text Search while migrating to Innodb ?
September 10, 2009 By 12 Comments
It is rather typical for systems to start as MyISAM but as system growths to move to Innodb. The reason of the move could be just desire for better data consistency guaranty or being bitten repairing multiple GB MyISAM table few times, though Table Locks is probably the most important issue – with modern multi [...]
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.
MySQL Quality of old and new features
October 4, 2007 By 24 Comments
Recent couple of days our team was pointed to number of bugs in MySQL 5.0 which again seriously shakes the confidence in both MySQL Quality Control and bug fix promptness. Let me just take couple of bugs as examples: Triggers broken with auto-increment columns for Innodb tables (bug 26316). As you can see this bug [...]
Using VIEW to reduce number of tables used
September 28, 2007 By 12 Comments
Many Open Source software solutions use database per user (or set of tables per user) which starts to cause problems if it is used on massive scale (blog hosting, forum hosting etc), resulting of hundreds of thousands if not millions of tables per server which can become really inefficient. It is especially inefficient with Innodb [...]
Are you designing IO bound or CPU bound application ?
December 20, 2006 By 10 Comments
This topic may look boring and obvious but it is extremely important for MySQL Performance Optimization. In fact I probably have to touch it in every second MySQL Consulting work or even more frequently. IO Bound workload is quite different from CPU bound one, which happens when your working set (normally only fraction of your [...]
Descending indexing and loose index scan
May 9, 2006 By 6 Comments
Comments to my previous posts, especially this one by Gokhan inspired me to write a bit about descending indexes and about loose index scan, or what Gokhan calls “better range” support. None of these are actially related to Innodb tables in general – these are features MySQL should get for all storage engines at some [...]
