May 19, 2013

Joining many tables in MySQL – optimizer_search_depth

Working on customer case today I ran into interesting problem – query joining about 20 tables (thank you ORM by joining all tables connected with foreign keys just in case) which would take 5 seconds even though in the read less than 1000 rows and doing it completely in memory. The plan optimizer picked was [...]

Percona welcomes Drizzle 7.1

The Drizzle team has published the first Drizzle 7.1 stable release. The announcement on the Drizzle blog covers some of the major improvements in this release over the previous stable release, Drizzle 7.0. I plan to write a variety of blog posts on each of the new features over the coming weeks. Major features include: Multi [...]

Is your MySQL Application having Busy IO by Oracle Measures ?

Preparing Choosing Storage Systems for MySQL talk for Percona Live in Washington,DC I ran into great paper called Sane SAN 2010 by James Morle from Scale Abilities – and Oracle consulting company. It is worth to read for variety of reason yet for this post I wanted to mention what James calls “Busy” Oracle database [...]

Hijacking Innodb Foreign Keys

I guess I’m first to post in 2012 so Happy New Year all blog readers ! Now back to HardCore MySQL business – foreign Keys. MySQL supported Foreign Keys for Innodb for many years, yet rudimentary support initially added in MySQL 3.23.44 have not been improved in new releases as much as I’d like. We [...]

Percona Xtrabackup 1.6.2 released!

Percona is glad to announce the release of Percona XtraBackup 1.6.2 on 25 July, 2011 (Downloads are available here and from thePercona Software Repositories). This release is purely composed of bug fixes and is the current stable release of Percona Xtrabackup. All of Percona’s software is open-source and free, all the details of the release and [...]

Aligning IO on a hard disk RAID – the Benchmarks

In the first part of this article I have showed how I align IO, now I want to share results of the benchmark that I have been running to see how much benefit can we get from a proper IO alignment on a 4-disk RAID1+0 with 64k stripe element. I haven’t been running any benchmarks [...]

Multiple purge threads in Percona Server 5.1.56 and MySQL 5.6.2

Part of the InnoDB duties, being an MVCC-implementing storage engine, is to get rid of–purge–the old versions of the records as they become obsolete.  In MySQL 5.1 this is done by the master InnoDB thread.  Since then, InnoDB has been moving towards the parallelized purge: in MySQL 5.5 there is an option to have a [...]

Performance Schema tables stats

My previous benchmark on Performance Schema was mainly in memory workload and against single tables. Now after adding multi-tables support to sysbench, it is interesting to see what statistic we can get from workload that produces some disk IO. So let’s run sysbench against 100 tables, each 5000000 rows (~1.2G ) and buffer pool 30G. [...]

Sample datasets for benchmarking and testing

Sometimes you just need some data to test and stress things. But randomly generated data is awful — it doesn’t have realistic distributions, and it isn’t easy to understand whether your results are meaningful and correct. Real or quasi-real data is best. Whether you’re looking for a couple of megabytes or many terabytes, the following [...]

Blog Redesign 2011

After more than four years of using a theme that can charitably be described as rustic, we’ve updated our look. We’re using the News theme from StudioPress, which is a bargain; their themes and theme framework are an engineering marvel. We’re still using the amazing Sphinx search plugin from Ivinco for fast and relevant searches. [...]