May 24, 2013

CentOS 5.8 users: your UTF-8 data is in peril with Perl MySQL

CentOS 5.8 and earlier use Perl module DBD::mysql v3.0007 which has a bug that causes Perl not to flag UTF-8 data as being UTF-8.  Presuming that the MySQL table/column is using UTF-8, and the Perl MySQL connection is also using UTF-8, then a correct system returns: PV = 0x9573840 "\343\203\213 \303\250"\0 [UTF8 "\x{30cb} \x{e8}"] That’s a Devel::Peek inside a Perl scalar variable which [...]

Analyzing Slow Query Table in MySQL 5.6

Next week I’m teaching an online Percona Training class, called Analyzing SQL Queries with Percona Toolkit.  This is a guided tour of best practices for pt-query-digest, the best tool for evaluating where your database response time is being spent. This month we saw the GA release of MySQL 5.6, and I wanted to check if any [...]

Percona Toolkit 2.1.9 is ready

About a month ago, we held a bug raffle for Percona Toolkit 2.1.9.  The turnout was good and the resulting release is worth upgrading to, especially if you were affected by the backwards-incompatible changes to pt-heartbeat in 2.1.8.  Here are the release notes for Percona Toolkit 2.1.9 which highlight the bugs fixed: Percona Toolkit 2.1.9 has been released. [...]

Webinar: Building a highly scaleable distributed row, document or column store with MySQL and Shard-Query

On Friday, February 15, 2013 10:00am Pacific Standard Time, I will be delivering a webinar entitled “Building a highly scaleable distributed row, document or column store with MySQL and Shard-Query” The first part of this webinar will focus on why distributed databases are needed, and on the techniques employed by Shard-Query to implement a distributed [...]

Feature preview: Compact backups in Percona XtraBackup

We continue to improve Percona XtraBackup, and today I would like to give a preview for one feature which comes in next Percona XtraBackup 2.1 release. This feature is “Compact backups”, and let me explain what it does. As you may know InnoDB PK (Primary Key) contains all data, and all secondary indexes are only [...]

Announcing Percona Server 5.1.66-14.2

Percona is glad to announce the release of Percona Server 5.1.66-14.2 on January 15th, 2013 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.1.66, including all the bug fixes in it, Percona Server 5.1.66-14.2 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 [...]

Sphinx search performance optimization: attribute-based filters

One of the most common causes of a poor Sphinx search performance I find our customers face is misuse of search filters. In this article I will cover how Sphinx attributes (which are normally used for filtering) work, when they are a good idea to use and what to do when they are not, but [...]

How does MySQL Replication really work?

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 [...]

Announcing Percona Server 5.5.28-29.3

Percona is glad to announce the release of Percona Server 5.5.28-29.3 on January 8th, 2012 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.5.28, including all the bug fixes in it, Percona Server 5.5.28-29.3 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 [...]