October 23, 2014

Tools and tips for analysis of MySQL’s Slow Query Log

MySQL has a nice feature, slow query log, which allows you to log all queries that exceed a predefined about of time to execute. Peter Zaitsev first wrote about this back in 2006 – there have been a few other posts here on the MySQL Performance Blog since then (check this and this, too) but […]

Percona Toolkit 2.1.11 is now available

Percona is glad to announce the release of Percona Toolkit 2.1.11 on March 4th, 2013 (Downloads are available here). Bugs Fixed: Fixed bug 1279502: –version-check behaves like spyware The configuration for what information Percona Toolkit should retrieve is not hard-coded in the scripts. Instead, it is downloaded from v.percona.com. One of the possible parameters was the name […]

How to monitor ALTER TABLE progress in MySQL

While working on a recent support issue as a Percona Support Engineer,  I got one question from a customer asking how to monitor ALTER TABLE progress. Actually, for MySQL 5.5 and prior versions, it’s quite difficult to ALTER the table in a running production environment especially for large tables (with millions records). Because it will rebuild and lock the table […]

Percona Toolkit collection: pt-visual-explain

This is the first in a series of posts highlighting a few of the seldom-used but still handy Percona Toolkit tools. Have you ever had a problem understanding the EXPLAIN statement output? And are you the type of person who would rather use the command line than a GUI application? Then I would recommend that […]

Percona Toolkit 2.2.6 is now available

Percona is glad to announce the release of Percona Toolkit 2.2.6 on December 20th, 2013 (Downloads are available here and from the Percona Software Repositories). This release is the current GA (Generally Available) stable release in the 2.2 series. This release has 16 bug fixes and a few new features. One bug fix is very important, so 2.2 users […]

Integrating pt-online-schema-change with a Scripted Deployment

Recently, I helped a client that was having issues with deployments causing locking in their production databases.  At a high level, the two key components used in the environment were: Capistrano (scripted deployments) [website] Liquibase (database version control) [website] At a high level, they currently used a CLI call to Liquibase as a sub-task within […]

Quick link to Percona Toolkit bugs

In this post I wanted to highlight percona.com/bugs/<tool> , for example: percona.com/bugs/pt-stalk.  This only works for Percona Toolkit.  We often advise people to check a tool’s current bugs, but we don’t always say how. The official link for Percona Toolkit bugs on Launchpad is https://bugs.launchpad.net/percona-toolkit/+bugs, but then you still have search from there.  So this quick link […]

How InnoDB promotes UNIQUE constraints

The other day I was running pt-duplicate-key-checker on behalf of a customer and noticed some peculiar recommendations on an InnoDB table with an odd structure (no PRIMARY key, but multiple UNIQUE constraints). This got me thinking about how InnoDB promotes UNIQUE constraints to the role of PRIMARY KEYs. The documentation is pretty clear: [DOCS] When […]

Want to archive tables? Use Percona Toolkit’s pt-archiver

Percona Toolkit’s pt-archiver is one of the best utilities to archive the records from large tables to another tables or files. One interesting thing is that pt-archiver is a read-write tool. It deletes data from the source by default, so after archiving you don’t need to delete it separately. As it is done by default, you […]

Percona Toolkit 2.1.10 is now available

Percona is glad to announce the release of Percona Toolkit 2.1.10 on July 18th, 2013 (Downloads are available here). Bugs Fixed: Unfortunately, the relatively new –utc option for pt-heart was still broken because “MySQL interprets date as a value in the current time zone and converts it to an internal value in UTC.” Now the tool works […]