April 19, 2014

Percona Toolkit version 2.1.6 released

The Percona Toolkit team is happy to announce the release of Percona Toolkit version 2.1.6. This is the sixth stable release in the 2.1 series, and primarily a bug-fix release; We suggest that users upgrade to the latest version of the tools. The complete list of changes is on the Launchpad milestone for 2.1.6, but […]

Knowing what pt-online-schema-change will do

pt-online-schema-change is simple to use, but internally it is complex.  Baron’s webinar about pt-online-schema-change hinted at several of the tool’s complexities.  Consequently, users often want to know before making changes what pt-online-schema-change will do when it runs.  The tool has two options to help answer this question: –dry-run and –print. When ran with –dry-run and –print, pt-online-schema-change changes nothing […]

Logging Foreign Key errors

In the last blog post I wrote about how to log deadlock errors using Percona Toolkit. Foreign key errors have the same problems. InnoDB only logs the last error in the output of SHOW ENGINE INNODB STATUS, so we need another similar tool in order to have historical data. pt-fk-error-logger This is a tool very […]

Full Text Search Webinar Questions Followup

I presented a webinar this week to give an overview of several Full Text Search solutions and compare their performance.  Even if you missed the webinar, you can register for it, and you’ll be emailed a link to the recording. During my webinar, a number of attendees asked some good questions.  Here are their questions and my […]

How to recover deleted rows from an InnoDB Tablespace

In my previous post I explained how it could be possible to recover, on some specific cases, a single table from a full backup in order to save time and make the recovery process more straightforward. Now the scenario is worse because we don’t have a backup or the backup restore process doesn’t work. How […]

STOP: DELETE IGNORE on Tables with Foreign Keys Can Break Replication

DELETE IGNORE suppresses errors and downgrades them as warnings, if you are not aware how IGNORE behaves on tables with FOREIGN KEYs, you could be in for a surprise. Let’s take a table with data as example, column c1 on table t2 references column c1 on table t1 – both columns have identical set of rows for […]

Hijacking Innodb Foreign Keys

I guess I’m first to post in 2012 so Happy New Year all blog readers ! Now back to HardCore MySQL business – foreign Keys. MySQL supported Foreign Keys for Innodb for many years, yet rudimentary support initially added in MySQL 3.23.44 have not been improved in new releases as much as I’d like. We […]

Percona Server 5.1.59-13.0

Percona is glad to announce the release of Percona Server 5.1.59-13.0 on October 15, 2011 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.1.59, including all the bug fixes in it, Percona Server 5.1.59-13.0 is now the current stable release in the 5.1 series. All of Percona’s software is open-source and free, all the […]

Percona Server 5.5.16-22.0

Percona is glad to announce the release of Percona Server 5.5.16-22.0 on October 14, 2011 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.5.16, including all the bug fixes in it, Percona Server 5.5.16-22.0 is now the current stable release in the 5.5 series. All of Percona’s software is open-source and free, all the […]

Flexviews – part 3 – improving query performance using materialized views

Combating “data drift” In my first post in this series, I described materialized views (MVs). An MV is essentially a cached result set at one point in time. The contents of the MV will become incorrect (out of sync) when the underlying data changes. This loss of synchronization is sometimes called drift. This is conceptually […]