May 24, 2013

ZFS on Linux and MySQL

May 24, 2013 By 5 Comments

I am currently working with a large customer and I am involved with servers located in two data centers, one with Solaris servers and the other one with Linux servers. The Solaris side is cleverly setup using zones and ZFS and this provides a very low virtualization overhead. I learned quite a lot about these [...]

Filed Under: Hardware and Storage, Insight for DBAs, MySQL Tagged With: , , , ,

Percona Server 5.5.30-30.2 rerelease fixes non-restart issue

April 24, 2013 By Leave a Comment

In our last 5.5 series release of Percona Server, we included a regression in the RPM packaging that prevented the server from restarting following an upgrade — instead, the server would remain stopped after the upgrade was completed regardless of its state before updating. This caused some problems for some users, especially if automatic upgrading was configured [...]

Filed Under: MySQL, Percona Software

High-load problems? Investigate them with ‘pt-query-digest’

April 23, 2013 By 2 Comments

I had the chance to work on an interesting case last week, and I thought I’d share what I think is a little known goodie from Percona Toolkit for MySQL called pt-query-digest. One customer was suffering from periods of high load on their database server, leading to degraded application performance, and sometimes even short moments [...]

Filed Under: MySQL Tagged With: , ,

How to recover table structure from InnoDB dictionary

April 22, 2013 By 4 Comments

To recover a dropped or corrupt table with Percona Data Recovery Tool for InnoDB you need two things: media with records(ibdata1, *.ibd, disk image, etc.) and a table structure. Indeed, there is no information about the table structure in an InnoDB page. Normally we either recover the structure from .frm files or take it from [...]

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MySQL 5.6 vs MySQL 5.5 and the Star Schema Benchmark

March 11, 2013 By 7 Comments

So far most of the benchmarks posted about MySQL 5.6 use the sysbench OLTP workload.  I wanted to test a set of queries which, unlike sysbench, utilize joins.  I also wanted an easily reproducible set of data which is more rich than the simple sysbench table.  The Star Schema Benchmark (SSB) seems ideal for this. [...]

Filed Under: MySQL Tagged With: , , , , ,

InnoDB Full-text Search in MySQL 5.6: Part 2, The Queries!

March 4, 2013 By 7 Comments

This is part 2 in a 3 part series. In part 1, we took a quick look at some initial configuration of InnoDB full-text search and discovered a little bit of quirky behavior; here, we are going to run some queries and compare the result sets. Our hope is that the one of two things [...]

Filed Under: Insight for DBAs, Insight for Developers, MySQL Tagged With: , , , , ,

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

February 26, 2013 By 1 Comment

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 [...]

Filed Under: Insight for DBAs, Insight for Developers, MySQL Tagged With: , , , , ,

Implications of Metadata Locking Changes in MySQL 5.5

February 1, 2013 By 9 Comments

While most of the talk recently has mostly been around the new changes in MySQL 5.6 (and that is understandable), I have had lately some very interesting cases to deal with, with respect to the Metadata Locking related changes that were introduced in MySQL 5.5.3. It appears that the implications of Metadata Locking have not [...]

Filed Under: Insight for DBAs, Insight for Developers, MySQL Tagged With: , , , , , ,

How does MySQL Replication really work?

January 9, 2013 By 9 Comments

While we do have many blog posts on replication on our blog, such as on replication being single-threaded, on semi-synchronous replication or on estimating replication capacity, I don’t think we have one that covers the very basics of how MySQL replication really works on the high level. Or it’s been so long ago I can’t [...]

Filed Under: Insight for DBAs, MySQL Tagged With: , ,

Be productive with the MySQL command line

December 21, 2012 By 14 Comments

Even if you are using a GUI tool to connect to your MySQL servers, one day or another, you will have to deal with the command line. So it is nice to know a few tips that can really make your work easier. Note: The commands below are only available for Unix/Linux. Using pager Most [...]

Filed Under: Insight for DBAs, MySQL
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