April 20, 2014

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 […]

Realtime stats to pay attention to in Percona XtraDB Cluster and Galera

I learn more and more about Galera every day.  As I learn more, I try to keep my myq_gadgets toolkit up to date with what I consider is important to keep any eye on on a PXC node.  In that spirit, I just today pushed some changes to the ‘wsrep’ report, and I thought I’d go over […]

Find unused indexes

I wrote one week ago about how to find duplicate indexes. This time we’ll learn how to find unused indexes to continue improving our schema and the overall performance. There are different possibilites and we’ll explore the two most common here. User Statistics from Percona Server and pt-index-usage. User Statistics User Statistics is an improvement […]

ALTER TABLE: Creating Index by Sort and Buffer Pool Size

Today I was looking at the ALTER TABLE performance with fast index creation and without it with different buffer pool sizes. Results are pretty interesting. I used modified Sysbench table for these tests because original table as initially created only has index on column K which initially contains only zeros, which means index is very […]

Find and remove duplicate indexes

Having duplicate keys in our schemas can hurt the performance of our database: They make the optimizer phase slower because MySQL needs to examine more query plans. The storage engine needs to maintain, calculate and update more index statistics DML and even read queries can be slower because MySQL needs update fetch more data to […]

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 5.1.58-12.9

Percona is glad to announce the release of Percona Server 5.1.58-12.9 on August 12, 2011 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.1.58, including all the bug fixes in it, Percona Server 5.1.58-12.9 is now the current stable release in the 5.1 series. All of Percona’s software is open-source and free, all […]

Thinking about running OPTIMIZE on your Innodb Table ? Stop!

Innodb/XtraDB tables do benefit from being reorganized often. You can get data physically laid out in primary key order as well as get better feel for primary key and index pages and so using less space, it is just OPTIMIZE TABLE might not be best way to do it. If you’re running Innodb Plugin on […]

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 is not […]

Drilling down to the source of the problem

I had an interesting tuning case few days ago. The system serving high traffic using Innodb tables would be stalling every so often causing even very simple queries both reads and writes taking long time to complete, with progress almost paused (dropping from thousands to tens of queries per second). On the surface the problem […]