The MySQL manual tells us that regardless of whether or not we use “SET FOREIGN_KEY_CHECKS=0″ before making schema changes, InnoDB will not allow a column referenced by a foreign key constraint to be modified in such a way that the foreign key will reference a column with a mismatched data type. For instance, if we [...]
Percona Toolkit versions 2.0.5 and 2.1.2 released
June 12, 2012 By 1 Comment
The Percona Toolkit team is happy to announce the release of Percona Toolkit versions 2.0.5 and 2.1.2. These are bug-fix releases in the 2.0 and 2.1 series, respectively. These releases fix many dozens of bugs, and we suggest that users upgrade to the latest versions of the tools. The complete list of changes is on [...]
Announcing Percona Server 5.5.24-26.0
June 1, 2012 By 9 Comments
Percona is glad to announce the release of Percona Server 5.5.24-26.0 on June 1st, 2012 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.5.24, including all the bug fixes in it, Percona Server 5.5.24-26.0 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 the release can [...]
Best kept MySQLDump Secret
March 23, 2012 By 13 Comments
Many people use mysqldump –single-transaction to get consistent backup for their Innodb tables without making database read only. In most cases it works, but did you know there are some cases when you can get table entirely missing from the backup if you use this technique ? The problem comes from the fact how MySQL’s [...]
Hijacking Innodb Foreign Keys
January 2, 2012 By 2 Comments
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 [...]
MySQL opening .frm even when table is in table definition cache
November 21, 2011 By 8 Comments
or… “the case of Stewart recognizing parameters to the read() system call in strace output”. Last week, a colleague asked a question: I have an instance of MySQL with 100 tables and the table_definition_cache set to 1000. My understanding of this is that MySQL won’t revert to opening the FRM files to read the table [...]
Improved InnoDB fast index creation
November 6, 2011 By 4 Comments
One of the serious limitations in the fast index creation feature introduced in the InnoDB plugin is that it only works when indexes are explicitly created using ALTER TABLE or CREATE INDEX. Peter has already blogged about it before, here I’ll just briefly reiterate other cases that might benefit from that feature: when ALTER TABLE [...]
Percona XtraBackup 1.6
April 12, 2011 By 15 Comments
Percona XtraBackup 1.6 is now available for download and is the current stable release version of XtraBackup.
Flexviews – part 3 – improving query performance using materialized views
April 4, 2011 By 20 Comments
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 [...]
Percona Server 5.5.10 (Release Candidate)
April 4, 2011 By 4 Comments
Percona Server release 5.5.10-20.1 is now available for download. This is a release candidate for the Percona Server 5.5 series. In addition to MySQL 5.5.10 now being the base version, here are the changes that have been made since Percona Server beta release 5.5.8-20.0:
