November 28, 2014

Upgrading MySQL

Upgrading MySQL Server is a very interesting task as you can approach it with so much different “depth”. For some this is 15 minutes job for others it is many month projects. Why is that ? Performing MySQL upgrade two things should normally worry you. It is Regressions – functionality regressions when what you’ve been […]

Air traffic queries in MyISAM and Tokutek (TokuDB)

This is next post in series Analyzing air traffic performance with InfoBright and MonetDB Air traffic queries in LucidDB Air traffic queries in InfiniDB: early alpha Let me explain the reason of choosing these engines. After initial three posts I am often asked “What is baseline ? Can we compare results with standard MySQL engines […]

Crashes while using MyISAM with multiple key caches

Over last couple of years I have ran into random MySQL crashes in production when multiple key caches were used. Unfortunately this never was frequent or critical enough issue so I could spend time creating repeatable test case and search of the bug in the MySQL database did not find anything. Recently we had this […]

MySQL 5.1 went to GA. Was it a good move ?

MySQL 5.1 release as “GA” seems to be the most controversial to date. It had very negative response from Monty, original MySQL Founder and controversial responses in community including another beating by Kevin Burton. There is also very interesting reading on MySQL 5.1 open bugs So how do I take it and where do I […]

Improved InnoDB rw_lock patch

There is patch from Google to improve SMP performance , but for some workloads it showed for us reverse scalability. E.g. update_key benchmark from sysbench. There are also results with Yasufumi’s rw_locks (http://bugs.mysql.com/bug.php?id=26442)

MySQL End Of Life (EOL) Policy

We’ve discussed today how we should implement MySQL Version advisory in mk-audit tool. One obvious questions was to look at the end of life – it is often bad idea to run MySQL versions past end of life as even security bugs may not be fixed in these (though do not get paranoid, if you’re […]

MySQL Architecture meeting at Google

Friday after MySQL Users Conference we had a smaller meeting at Google campus to talk about MySQL architecture mainly focusing on storage engine vendors and other extension areas. It was very interesting to see all these storage engine interface extensions which are planned for MySQL 6.0 and beyond – abilities to intercept query execution or […]

MySQL 6.0 Subquery optimizations are published.

Sergey Petrunia brought to my attention the work Optimizer Team has done in MySQL 6.0 related to SubQuery Optimization. I am excited to see this information published honestly outlining the things which are fixed now and things which are still not handled well. According to the bug sampling done by Optimizer Team 68% of reported […]

Finding out largest tables on MySQL Server

Finding largest tables on MySQL instance is no brainier in MySQL 5.0+ thanks to Information Schema but I still wanted to post little query I use for the purpose so I can easily find it later, plus it is quite handy in a way it presents information:

What is the longest part of Innodb Recovery Process ?

In MySQL 4.1 and above the longest part of recovery after crash for Innodb tables could be UNDO stage – it was happening in foreground and was basically unbound – if you have large enough transaction which needed to be undone this could take long hours. REDO stage on other hand always could be regulated […]