Thanks to all who attended my webinar today. The session was recorded and will be available to watch for free soon here. There were a lot of great questions asked during the session, so I’d like to take this opportunity to try to answer a few of them: Q: Is there an easy way to [...]
How to diagnose errors in the MySQL error log
I frequently see questions about how to understand the nature of errors in MySQL’s error log. Now, there is a lot of complexity to this — the flowchart would be quite large, as with any nontrivial piece of software. But there is one particular class of errors that is relatively easy to diagnose, if you [...]
How FLUSH TABLES WITH READ LOCK works with Innodb Tables
Many backup tools including Percona Xtrabackup, MyLVMBackup and others use FLUSH TABLES WITH READ LOCK to temporary make MySQL read only. In many cases the period for which server has to be made read only is very short, just few seconds, yet the impact of FLUSH TABLES WITH READ LOCK can be quite large because [...]
Troubleshooting MySQL Upgrade Performance Regressions
So lets say you upgraded from MySQL 5.1 to Percona Server 5.5 and instead of expected performance improvement you see your performance being worse. What should you do ? First if you followed MySQL upgrade best practices such as testing your workload with pt-upgrade the chances of this happening are rather slim. But lets assume [...]
How to recover a single InnoDB table from a Full Backup
Sometimes we need to restore only some tables from a full backup maybe because your data loss affect a small number of your tables. In this particular scenario is faster to recover single tables than a full backup. This is easy with MyISAM but if your tables are InnoDB the process is a little bit [...]
Percona Server 5.1.60-13.1
Percona is glad to announce the release of Percona Server 5.1.60-13.1 on December 16, 2011 (Downloads are available from Percona Server 5.1.60-13.1 downloads and from the Percona Software Repositories). Based on MySQL 5.1.60, including all the bug fixes in it, Percona Server 5.1.60-13.1 is now the current stable release in the 5.1 series. All of Percona ‘s software is open-source and free, all the details [...]
Percona Server 5.5.17-22.1 released
Percona is glad to announce the release of Percona Server 5.5.17-22.1 on November 19th, 2011 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.5.17, including all the bug fixes in it, Percona Server 5.5.17-22.1 is now the current stable release in the 5.5 series. All of Percona ‘s software is open-source and free, all the details of the release can [...]
Dynamic row format for MEMORY tables
The latest Percona Server release has one new feature: now MEMORY tables can have BLOB and TEXT columns, and VARCHAR columns will not waste space due to implicit extension to CHAR.
Aligning IO on a hard disk RAID – the Benchmarks
In the first part of this article I have showed how I align IO, now I want to share results of the benchmark that I have been running to see how much benefit can we get from a proper IO alignment on a 4-disk RAID1+0 with 64k stripe element. I haven’t been running any benchmarks [...]
The case for getting rid of duplicate “sets”
The most useful feature of the relational database is that it allows us to easily process data in sets, which can be much faster than processing it serially. When the relational database was first implemented, write-ahead-logging and other technologies did not exist. This made it difficult to implement the database in a way that matched [...]

