Monthly Archives - May 2010

Percona Welcomes Justin Swanhart

Percona is pleased to officially welcome Justin Swanhart to our team of consultants.
Before joining Percona, Justin worked as a MySQL DBA at Gazillion, Yahoo, and Kickfire. Justin has become a regular contributor here on the MySQL Performance Blog as well as being an active blogger at http://swanhart.livejournal.com/. He is very active in […]

Read more

Disk seeks are evil, so let’s avoid them, pt. 2

In part 1, I discussed why having many disk seeks are bad (they slow down performance), and how fractal tree data structures minimize disk seeks on ad-hoc insertions, whereas B-trees practically guarantee that disk seeks are performed on ad-hoc insertions. As a result, fractal tree data structures can insert data up to two orders […]

Read more

Tuning InnoDB Concurrency Tickets

InnoDB has an oft-unused parameter innodb_concurrency_tickets that seems widely misunderstood. From the docs: “The number of threads that can enter InnoDB concurrently is determined by the innodb_thread_concurrency variable. A thread is placed in a queue when it tries to enter InnoDB if the number of threads has already reached the concurrency […]

Read more

Percona Server security fix releases

As you may know MySQL ® announced 5.0.91 and 5.1.47 with serious security fixes, so we provide binary releases of Percona Server 5.0 and Percona Server / XtraDB 5.1 with security patches.
Fixed bugs:

Bug#53371, CVE-2010-1848
Bug#53237, CVE-2010-1850
Bug#50974, CVE-2010-1849

Release Percona Server 5.0.91-rel22 is available in our download area:
https://www.percona.com/downloads/Percona-Server-5.0/Percona-Server-5.0.91-22/

Release Percona Server/XtraDB 5.1.45-rel10.2 is available also ( we backported […]

Read more

Extending Index for Innodb tables can hurt performance in a surprising way

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 […]

Read more

A workaround for the performance problems of TEMPTABLE views

MySQL supports two different algorithms for views: the MERGE algorithm and the TEMPTABLE algorithm. These two algorithms differ greatly. A view which uses the MERGE algorithm can merge filter conditions into the view query itself. This has significant performance advantages over TEMPTABLE views. A view which uses the TEMPTABLE algorithm […]

Read more