May 19, 2013

MySQL 5.6 vs MySQL 5.5 and the Star Schema Benchmark

March 11, 2013 By 7 Comments

So far most of the benchmarks posted about MySQL 5.6 use the sysbench OLTP workload.  I wanted to test a set of queries which, unlike sysbench, utilize joins.  I also wanted an easily reproducible set of data which is more rich than the simple sysbench table.  The Star Schema Benchmark (SSB) seems ideal for this. [...]

Filed Under: MySQL Tagged With: , , , , ,

Sphinx search performance optimization: attribute-based filters

January 15, 2013 By 9 Comments

One of the most common causes of a poor Sphinx search performance I find our customers face is misuse of search filters. In this article I will cover how Sphinx attributes (which are normally used for filtering) work, when they are a good idea to use and what to do when they are not, but [...]

Filed Under: Insight for Developers, MySQL Tagged With: , ,

CVE-2012-4414 strikes back in MySQL 5.5.29 (and what we’re doing in Percona Server 5.5.29)

January 13, 2013 By 4 Comments

In preparing Percona Server 5.5.29 (not yet released, but soon), I filed MySQL bug 68045 (is marked private as it’s a security bug). This bug is in relation to the Oracle fix for CVE-2012-4414 and a problem I found with it. The MariaDB fix (which we incorporated into Percona Server 5.5.28-29.3) is not affected. When the [...]

Filed Under: MySQL, Percona Software Tagged With: , ,

Can we improve MySQL variable handling ?

February 18, 2012 By 8 Comments

MySQL Settings (also known as Server Variables) have interesting property. When you set variable in running server this change is not persisted in any way and server will be back to old value upon restart. MySQL also does not have option to re-read config file without restarting as some other software so approach to change [...]

Filed Under: MySQL

Should we give a MySQL Query Cache a second chance ?

April 10, 2011 By 64 Comments

Over last few years I’ve been suggesting more people to disable Query Cache than to enable it. It can cause contention problems as well as stalls and due to coarse invalidation is not as efficient as it could be. These are however mostly due to neglect Query Cache received over almost 10 years, with very [...]

Filed Under: Insight for DBAs, MySQL

Ultimate MySQL variable and status reference list

January 8, 2011 By 4 Comments

I am constantly referring to the amazing MySQL manual, especially the option and variable reference table. But just as frequently, I want to look up blog posts on variables, or look for content in the Percona documentation or forums. So I present to you what is now my newest Firefox toolbar bookmark: an option and [...]

Filed Under: Insight for DBAs, MySQL

Air traffic queries in InfiniDB: early alpha

November 2, 2009 By 19 Comments

As Calpont announced availability of InfiniDB I surely couldn’t miss a chance to compare it with previously tested databases in the same environment. See my previous posts on this topic: Analyzing air traffic performance with InfoBright and MonetDB Air traffic queries in LucidDB I could not run all queries against InfiniDB and I met some [...]

Filed Under: Benchmarks, MySQL Tagged With: ,

Quick comparison of MyISAM, Infobright, and MonetDB

September 29, 2009 By 30 Comments

Recently I was doing a little work for a client who has MyISAM tables with many columns (the same one Peter wrote about recently). The client’s performance is suffering in part because of the number of columns, which is over 200. The queries are generally pretty simple (sums of columns), but they’re ad-hoc (can access [...]

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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 [...]

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