August 1, 2014

How to reclaim space in InnoDB when innodb_file_per_table is ON

When innodb_file_per_table is OFF and all data is going to be stored in ibdata files. If you drop some tables of delete some data then there is no any other way to reclaim that unused disk space except dump/reload method. When Innodb_file_per_table is ON, each table stores data and indexes in it’s own tablespace file. […]

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 […]

MySQL and the SSB – Part 2 – MyISAM vs InnoDB low concurrency

This blog post is part two in what is now a continuing series on the Star Schema Benchmark. In my previous blog post I compared MySQL 5.5.30 to MySQL 5.6.10, both with default settings using only the InnoDB storage engine.  In my testing I discovered that innodb_old_blocks_time had an effect on performance of the benchmark.  There was […]

Percona Server for MySQL 5.5.30-30.2 now available

Percona is glad to announce the release of Percona Server for MySQL 5.5.30-30.2 on April 10, 2013 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.5.30, including all the bug fixes in it, Percona Server 5.5.30-30.2 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 […]

5 Percona Toolkit Tools for MySQL That Could Save Your Day: April 3 Webinar

On April 3 at 10 a.m. PST, I’ll be giving a webinar titled “5 Percona Toolkit Tools for MySQL That Could Save Your Day.” In this presentation you’ll learn how to perform typical but challenging MySQL database administration tasks. My focus will be on the following tools: pt-query-digest, to select the queries you should try […]

InnoDB Full-text Search in MySQL 5.6 (part 1)

I’ve never been a very big fan of MyISAM; I would argue that in most situations, any possible advantages to using MyISAM are far outweighed by the potential disadvantages and the strengths of InnoDB. However, up until MySQL 5.6, MyISAM was the only storage engine with support for full-text search (FTS). And I’ve encountered many […]

MySQL 5.5 and MySQL 5.6 default variable values differences

As the part of analyzing surprising MySQL 5.5 vs MySQL 5.6 performance results I’ve been looking at changes to default variable values. To do that I’ve loaded the values from MySQL 5.5.30 and MySQL 5.6.10 to the different tables and ran the query:

Lets go over to see what are the most important changes […]

MySQL 5.6: Improvements in the Nutshell

Preparing for my talk for Percona MySQL University in Raleigh,NC, Tuesday 29th of January I have created the outline of improvements available in MySQL 5.6 which I thought was worth sharing to give a feel for how massive work have been done for this release in variety of areas. I’m sure the list is not […]

Is there room for more MySQL IO Optimization?

I prefer to run MySQL with innodb_flush_method=O_DIRECT in most cases – it makes sure there is no overhead of double buffering and I can save the limited amount of file system cache I would normally have on database server for those things which need to be cached — system files, binary log, FRM files, MySQL […]

How to find MySQL queries worth optimizing ?

One question I often get is how one can find out queries which should be optimized. By looking at pt-query-digest report it is easy to find slow queries or queries which cause the large portion of the load on the system but how do we know whenever there is any possibility to make this query […]