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 [...]
MySQL Backup tools used by Percona Remote DBA for MySQL
March 13, 2013 By 8 Comments
As part of Percona Remote DBA for MySQL service we recognize that reliable backups are one of the most important things we can bring to the table. In my experience handling emergencies, the single worst thing that can happen is finding out you don’t have backups available when some sort of data loss or catastrophic [...]
Can’t Create Thread: Errno 11 (A Tale of Two Ulimits)
February 4, 2013 By 10 Comments
Recently some of my fellow Perconians and I have noticed a bit of an uptick in customer cases featuring the following error message:
1 2 | SQLSTATE[HY000] [1135] Can't create a new thread (errno 11); if you are not out of available memory, you can consult the manual for a possible OS-dependent bug. |
The canonical solution to this issue, if you do a bit of Googling, is to increase the number of processes / threads available to the MySQL user, typically by adding a [...]
Concatenating MyISAM files
November 19, 2012 By 5 Comments
Recently, I found myself involved in the migration of a large read-only InnoDB database to MyISAM (eventually packed). The only issue was that for one of the table, we were talking of 5 TB of data, 23B rows. Not small… I calculated that with something like insert into MyISAM_table… select * from Innodb_table… would take [...]
Review of MySQL 5.6 Defaults Changes
October 8, 2012 By 10 Comments
James Day just posted the great summary of defaults changes in MySQL 5.6 compared to MySQL 5.5 In general there are a lot of good changes and many defaults are now computed instead of hardcoded. Though some of changes are rather puzzling for me. Lets go over them: back_log = 50 + ( max_connections / [...]
Announcing Percona Server 5.1.65-14.0
September 4, 2012 By Leave a Comment
Percona is glad to announce the release of Percona Server 5.1.65-14.0 on September 4th, 2012 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.1.65, including all the bug fixes in it, Percona Server 5.1.65-14.0 is now the current stable release in the 5.1 series. All of Percona‘s software is open-source and free, all the details of the release can [...]
MySQL Indexing Best Practices: Webinar Questions Followup
August 16, 2012 By 4 Comments
I had a lot of questions on my MySQL Indexing: Best Practices Webinar (both recording and slides are available now) We had lots of questions. I did not have time to answer some and others are better answered in writing anyway. Q: One developer on our team wants to replace longish (25-30) indexed varchars with [...]
Solving INFORMATION_SCHEMA slowness
December 23, 2011 By 25 Comments
Many of us find INFORMATION_SCHEMA painfully slow to work it when it comes to retrieving table meta data. Many people resort to using file system tools instead to find for example how much space innodb tables are using and things like it. Besides being just slow accessing information_schema can often impact server performance dramatically. The [...]
Four ways to optimize paginated displays
September 24, 2008 By 27 Comments
A paginated display is one of the top optimization scenarios we see in the real world. Search results pages, leaderboards, and most-popular lists are good examples. You know the design pattern: display 20 results in some most-relevant order. Show a “next” and “previous” link. And usually, show how many items are in the whole list [...]
Heikki Tuuri Innodb answers – Part I
October 26, 2007 By 19 Comments
Its almost a month since I promised Heikki Tuuri to answer Innodb Questions. Heikki is a busy man so I got answers to only some of the questions but as people still poking me about this I decided to publish the answers I have so far. Plus we may get some interesting follow up questions [...]
