Prior to version 5.0, MySQL could only use one index per table in a given query without any exceptions; folks that didn’t understand this limitation would often have tables with lots of single-column indexes on columns which commonly appeared in their WHERE clauses, and they’d wonder why the EXPLAIN plan for a given SELECT would […]
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 […]
This is the third blog post in the series of blog posts leading up to the talk comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. This blog post is targeted at the join related optimizations introduced in the optimizer. These optimizations are available in both MySQL 5.6 and MariaDB 5.5, and MariaDB 5.5 […]
Next Wednesday, March-21, 11:00am Pacific Time, Baron and me will be co-presenting with Virident webinar: “How to Turbocharge Your MySQL Performance Using Flash Storage” (From Virident side: Shridar Subramanian and Shirish Jamthe).
I have been working with Peter in preparation for the talk comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. We are taking a look at and benchmarking optimizer enhancements one by one. So in the same way this blog post is aimed at a new optimizer enhancement Index Condition Pushdown (ICP). Its available […]
Combating “data drift” In my first post in this series, I described materialized views (MVs). An MV is essentially a cached result set at one point in time. The contents of the MV will become incorrect (out of sync) when the underlying data changes. This loss of synchronization is sometimes called drift. This is conceptually […]
One schema optimization we often do is extending index when there are queries which can use more key part. Typically this is safe operation, unless index length increases dramatically queries which can use index can also use prefix of the new index are they ? It turns there are special cases when this is not […]
Recently I looked at table_cache sizing which showed larger table cache does not always provides the best performance. So I decided to look at yet another similar variable – innodb_open_files which defines how many files Innodb will keep open while working in innodb_file_per_table mode. Unlike MyISAM Innodb does not have to keep open file descriptor […]
MySQL 5.4 comes with Innodb engine which seems to have much better performance than MySQL 5.0 – this is due to locking and IO patches from Google integrated in this release (which are similar to appropriate Percona patches) as well as some unique fixes such as different innodb_thread_concurrency handling and other optimization. Should we take […]
…any sessions this year; Peter, Vadim, and the rest of us at Percona submitted over a dozen session proposals, which were initially declined. As …Cabral is organizing.
That’s the back story — now on to the Percona Performance Conference! This is not “another MySQL conference.” It’s a performance…to Santa Clara.
We will not be the only ones speaking at Percona Performance Conference; other experts will join us in making presentations too. …to propose a session, please do so through the Percona Performance Conference website.
The Percona team looks forward to greeting you face to face …