June 19, 2013

Innodb undo segment size and transaction isolation

You might know if you have long running transactions you’re risking having a lot of “garbage” accumulated in undo segment size which can cause performance degradation as well as increased disk space usage. Long transactions can also be bad for other reasons such as taking row level locks which will prevent other transactions for execution, [...]

High Rate insertion with MySQL and Innodb

I again work with the system which needs high insertion rate for data which generally fits in memory. Last time I worked with similar system it used MyISAM and the system was built using multiple tables. Using multiple key caches was the good solution at that time and we could get over 200K of inserts/sec. [...]

Spreading .ibd files across multiple disks; the optimization that isn’t

Inspired by Baron’s earlier post, here is one I hear quite frequently – “If you enable innodb_file_per_table, each table is it’s own .ibd file.  You can then relocate the heavy hit tables to a different location and create symlinks to the original location.” There are a few things wrong with this advice:

Percona XtraBackup 1.5-Beta

Percona XtraBackup 1.5-Beta is now available for download. This release adds additional functionality to Percona XtraBackup 1.4, the current general availability version of XtraBackup. This is a beta release. Functionality Added or Changed Support for MySQL 5.5 databases has been implemented. (Yasufumi Kinoshita) XtraBackup can now be built from the MySQL 5.1.52, MySQL 5.5.7, or Percona Server [...]

MySQL Partitioning – can save you or kill you

I wanted for a while to write about using MySQL Partitioning for Performance Optimization and I just got a relevant customer case to illustrate it. First you need to understand how partitions work internally. Partitions are on the low level are separate table. This means when you’re doing lookup by partitioned key you will look [...]

How well does your table fits in innodb buffer pool ?

Understanding how well your tables and indexes fit to buffer pool are often very helpful to understand why some queries are IO bound and others not – it may be because the tables and indexes they are accessing are not in cache, for example being washed away by other queries. MySQL Server does not provide [...]

Thinking about running OPTIMIZE on your Innodb Table ? Stop!

Innodb/XtraDB tables do benefit from being reorganized often. You can get data physically laid out in primary key order as well as get better feel for primary key and index pages and so using less space, it is just OPTIMIZE TABLE might not be best way to do it. If you’re running Innodb Plugin on [...]

Speaking on San Francisco Meetup 14-Dec : What’s new in XtraDB/InnoDB-plugin 5.1+

Erin and Mike, organizers of SF Meetup generously invited me to talk on coming SF Meetup on Dec-14 about new features in InnoDB in MySQL 5.1 and 5.5 and, what is pay attention to, when you upgrade from MySQL 5.0. Although I personally mostly in 5.1->5.5 upgrade area, Erin insured me that upgrade from MySQL [...]

Moving from MyISAM to Innodb or XtraDB. Basics

I do not know if it is because we’re hosting a free webinar on migrating MyISAM to Innodb or some other reason but recently I see a lot of questions about migration from MyISAM to Innodb. Webinar will cover the process in a lot more details though I would like to go over basics in [...]

Percona XtraBackup 1.4

Percona XtraBackup 1.4 is now available for download. Version 1.4 fixes problems related to incremental backups. If you do incremental backups, it’s strongly recommended that you upgrade to this release. Functionality Added or Changed Incremental backups have changed and now allow the restoration of full backups containing certain rollback transactions that previously caused problems. Please [...]