May 20, 2013

MySQL 5.6.10 Optimizer Limitations: Index Condition Pushdown

While preparing the webinar I will deliver this Friday, I ran into a quite interesting (although not very impacting) optimizer issue: a “SELECT *” taking half the time to execute than the same “SELECT one_indexed_column” query in MySQL 5.6.10. This turned into a really nice exercise for checking the performance and inner workings of one [...]

Announcing Percona Server for MySQL 5.5.30-30.1

Percona is glad to announce the release of Percona Server for MySQL 5.5.30-30.1 on March 7, 2013 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.5.30, including all the bug fixes in it, Percona Server 5.5.30-30.1 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 [...]

Percona Welcomes MySQL 5.6!

MySQL 5.6 was made generally available as a production-ready solution earlier this month. This release comes about 2 years after MySQL 5.5 was released, but MySQL 5.6 contains improvements started long before that – for example, work on the Innodb Full Text Search project was started over 6 years ago, in addition with many optimizer [...]

Percona MySQL Webinar: Really Large Queries: Advanced Optimization Techniques, Feb. 27

Do you have a query you never dared to touch? Do you know it’s bad, but it’s needed? Does it fit your screen? Does it really have to be that expensive? Do you want to do something about it? During the next Percona webinar on February 27, I will present some techniques that can be [...]

Is MySQL 5.6 slower than MySQL 5.5?

There have been a number reports/benchmarks showing MySQL 5.6 to be slower than MySQL 5.5 on variety of workloads. There are many possible reasons and I believe we will learn about many of them in the next few weeks and months as MySQL 5.6 is starting to get production battle-tested and there is inflow of [...]

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 [...]

Join us for our first Percona MySQL University event in Raleigh, N.C. Jan 29

At Percona we focus on education a lot, which we believe is critical for us to be successful with our mission of making businesses successful with their use of MySQL. The MySQL Performance Blog, our first effort in this space, by now contains over 1,000 technical articles. We have spoken on countless conferences and Meetups [...]

Is there room for more MySQL IO Optimization?

I prefer to run MySQL with innodb_flush_method=O_DIRECT in most cases – it makes sure there is no overhead of double buffering and I can save the limited amount of file system cache I would normally have on database server for those things which need to be cached — system files, binary log, FRM files, MySQL [...]

Full table scan vs full index scan performance

Earlier this week, Cédric blogged about how easy we can get confused between a covering index and a full index scan in the EXPLAIN output. While a covering index (seen with EXPLAIN as Extra: Using index) is a very interesting performance optimization, a full index scan (type: index) is according to the documentation the 2nd [...]

Tools and Techniques for Index Design Webinar Questions Followup

I presented a webinar this week to give an overview of Tools and Techniques for Index Design. Even if you missed the webinar, you can register for it, and you’ll be emailed a link to the recording. I’d like to invite folks who are interested in tools for query optimization to attend the new Percona [...]