July 25, 2014

Logging MySQL queries from the client instead of the server

The “slow query log” is the single most valuable way to examine query execution on your MySQL server. Queries are logged with timing information, and in the case of Percona Server, a great deal of additional performance and other diagnostic information. But the execution time recorded in the log is the time the query took […]

The story of one MySQL Upgrade

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 […]

mysql_upgrade and Innodb Tables

Upgrading from MySQL 5.0 to MySQL 5.1 or Percona Server 5.1 you may run into issues with mysql_upgrade – it will identify some tables to be upgraded and will attempt to run REPAIR TABLE for them. This will fail with “The storage engine for the table doesn’t support repair” error message. This seems to confuse […]

Upgrading MySQL

Upgrading MySQL Server is a very interesting task as you can approach it with so much different “depth”. For some this is 15 minutes job for others it is many month projects. Why is that ? Performing MySQL upgrade two things should normally worry you. It is Regressions – functionality regressions when what you’ve been […]

How Percona does a MySQL Performance Audit

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 […]

MySQL Stored Procedures problems and use practices

To be honest I’m not a big fan of Stored Procedures, At least not in the form they are currently implemented in MySQL 5.0 Only SQL as a Language Which is ancient ugly for algorithmic programming and slow. It is also forces you to use a lot of foreign constructs to “original” MySQL style – […]

Predicting how long data load would take

I had this question asked many times during last week, and there is really no easy answer. There are just way too many variables to consider especially while loading large schemas with a lot of different table structures. So which variables affect the load speed: Table Structure This one is tricky. The shorter rows you […]

Introducing backup locks in Percona Server

TL;DR version: The backup locks feature introduced in Percona Server 5.6.16-64.0 is a lightweight alternative to FLUSH TABLES WITH READ LOCK and can be used to take both physical and logical backups with less downtime on busy servers. To employ the feature with mysqldump, use mysqldump –lock-for-backup –single-transaction. The next release of Percona XtraBackup will […]

InnoDB performance optimization basics (redux)

I recently stumbled upon a post that Peter Zaitsev published back in 2007 titled “Innodb Performance Optimization Basics.” It’s a great post and reading it inspired me to examine what’s changed in the nearly six years that have followed in terms of MySQL, Percona Server – as well as in all of the other now-available […]

How to recover table structure from InnoDB dictionary

To recover a dropped or corrupt table with Percona Data Recovery Tool for InnoDB you need two things: media with records(ibdata1, *.ibd, disk image, etc.) and a table structure. Indeed, there is no information about the table structure in an InnoDB page. Normally we either recover the structure from .frm files or take it from […]