MySQL supports two different algorithms for views: the MERGE algorithm and the TEMPTABLE algorithm. These two algorithms differ greatly. A view which uses the MERGE algorithm can merge filter conditions into the view query itself. This has significant performance advantages over TEMPTABLE views. A view which uses the TEMPTABLE algorithm will have to compute the [...]
Faster MySQL failover with SELECT mirroring
February 1, 2009 By 9 Comments
One of my favorite MySQL configurations for high availability is master-master replication, which is just like normal master-slave replication except that you can fail over in both directions. Aside from MySQL Cluster, which is more special-purpose, this is probably the best general-purpose way to get fast failover and a bunch of other benefits (non-blocking ALTER [...]
High-Performance Click Analysis with MySQL
December 22, 2008 By 13 Comments
We have a lot of customers who do click analysis, site analytics, search engine marketing, online advertising, user behavior analysis, and many similar types of work. The first thing these have in common is that they’re generally some kind of loggable event. The next characteristic of a lot of these systems (real or planned) is [...]
How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
Our customers or prospective customers often ask us how we do a performance audit (it’s our most popular service). I thought I should write a blog post that will both answer their question, so I can just reply “read all about it at this URL” and share our methodology with readers a little bit. This [...]
Neat tricks for the MySQL command-line pager
June 23, 2008 By 12 Comments
How many of you use the mysql command-line client? And did you know about the pager command you can give it? It’s pretty useful. It tells mysql to pipe the output of your commands through the specified program before displaying it to you. Here’s the most basic thing I can think of to do with [...]
Updated msl (microslow) patch, installation walk-through!
April 20, 2008 By 17 Comments
For a couple of months there have been no updates to our msl patch, however recently I managed some time to change this. The functionality was extended a little bit and what’s even more important the patch is available for all the recent MySQL releases. To remind anyone who has not yet come across this [...]
Large result sets vs. compression protocol
December 20, 2007 By 6 Comments
mysql_connect() function in PHP’s MySQL interface (which for reference maps to mysql_real_connect() function in MySQL C API) has a $client_flags parameter since PHP 4.3.0. This parameter is barely known and almost always overlooked but in some cases it could provide a nice boost to your application. There’s a number of different flags that can be [...]
Heikki Tuuri Innodb answers – Part I
October 26, 2007 By 19 Comments
Its almost a month since I promised Heikki Tuuri to answer Innodb Questions. Heikki is a busy man so I got answers to only some of the questions but as people still poking me about this I decided to publish the answers I have so far. Plus we may get some interesting follow up questions [...]
Working with large data sets in MySQL
July 5, 2007 By 12 Comments
What does working with large data sets in mySQL teach you ? Of course you have to learn a lot about query optimization, art of building summary tables and tricks of executing queries exactly as you want. I already wrote about development and configuration side of the problem so I will not go to details [...]
Performance impact of complex queries
January 17, 2007 By 11 Comments
What is often underestimated is impact of MySQL Performance by complex queries on large data sets(ie some large aggregate queries) and batch jobs. It is not rare to see queries which were taking milliseconds to stall for few seconds, especially in certain OS configurations, and on low profile servers (ie having only one disk drive) [...]
