May 24, 2013

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

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 [...]

Edge-case behavior of INSERT…ODKU

A few weeks back, I was working on a customer issue wherein they were observing database performance that dropped through the floor (to the point of an outage) roughly every 4 weeks or so. Nothing special about the environment, the hardware, or the queries; really, the majority of the database was a single table with [...]

How to obtain the “LES” (Last Executed Statement) from an Optimized Core Dump?

Ever ran into a situation where you saw “some important variable you really needed to know about=<optimized out>” while debugging?

Visualization tools for pt-query-digest tables

When you process MySQL slow query logs using pt-query-digest you can store samples of each query into query_review table and historical values for review trend analysis into query_review_history table. But it could be difficult to easily browse those tables without a good GUI tool. For the visual browsing of tables created by pt-query-digest you may [...]

SQL Injection Questions Followup

I presented a webinar today about SQL Injection, to try to clear up some of the misconceptions that many other blogs and articles have about this security risk.  You can register for the webinar even now that I’ve presented it, and you’ll be emailed a link to the recording, which will be available soon. During [...]

Improved InnoDB fast index creation

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 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 [...]

Ultimate MySQL variable and status reference list

I am constantly referring to the amazing MySQL manual, especially the option and variable reference table. But just as frequently, I want to look up blog posts on variables, or look for content in the Percona documentation or forums. So I present to you what is now my newest Firefox toolbar bookmark: an option and [...]

EXPLAIN EXTENDED can tell you all kinds of interesting things

While many people are familiar with the MySQL EXPLAIN command, fewer people are familiar with “extended explain” which was added in MySQL 4.1 EXPLAIN EXTENDED can show you what the MySQL optimizer does to your query. You might not know this, but MySQL can dramatically change your query before it actually executes it. This process [...]