MySQL Performance Blog

One command, which few people realize exists is SHOW OPEN TABLES - it allows you to examine what tables do you have open right now:

As you might have seen MySQL QA Team has published their benchmarks for MySQL 5.0.72 and 5.1.30.

It is interesting to compare with results I posted previously

The quote from the results mentioned above:

I had a call with Monty the other day and I told him why I think MySQL Server Quality will never be the same again. I’ve been thinking a bit more about it and here is the extended list.

Well, actually it is not reading future, but just mysql-5.1.30.rhel4.spec file from MySQL RedHat 4 SRPM.

I found there few MySQL Enterprise Editions, namely:

MySQL Enterprise Server - Advanced Edition
MySQL Enterprise Server - Pro Edition
MySQL Enterprise Server - Classic Edition

What is difference ? Let’s see.

For MySQL Enterprise Server - Advanced Edition:
%define PARTITION_BUILD 1
%define INNODB_BUILD 1

One typical question which frequently pops up is whenever it is better to use hardware upgrade or optimize software more. I already wrote about it, for example here.

Today I’ll look at the same topic from the consultants view. When consultant should suggest hardware upgrade and when it is not in a simple checklist form.

We’ve recently done benchmarks comparing different MySQL versions in terms of their CPU efficiently in TPC-C like Workload. We did it couple of weeks ago so MySQL 5.0.67, MySQL 5.1.29 and Innodb Plugin 1.0.1 were used which are not very recent, though we do not think results will differ a lot with today versions.

Results are as follows:

When doing performance analyzes you often would want to see 95 percentile, 99 percentile and similar values. The "average" is the evil of performance optimization and often as helpful as "average patient temperature in the hospital".

Lets set you have 10000 page views or queries and have average response time of 1 second. What does it mean ? Really nothing - may be one page view was 10000 seconds and the rest was in low milliseconds or may be you had every single page view taking 1 second, which are completely different.

There are all sorts of different interfaces to memcached, but you don't need any of them to make requests from the command line, because its protocol is so simple. Try this, assuming it's running on the usual port on the local machine:

I have written before - MyISAM Does Not Scale, or it does quite well - two main things stopping you is table locks and global mutex on the KeyCache.

INFORMATION_SCHEMA, in particular by favorite TABLES table is not only helpful to understand tables you have on the system, but I have also found it to be very helpful as a scripting language for variety of database administration tasks. It can be more straightforward compared to using shell or Perl when the operation is database specific.

For example if you would like to MySQLDump only Innodb table in one file per database you can do the following:

After some discussions on the OpenSQLCamp 2008 conference we decided to move our development to Launchpad, to be in stream with other MySQL related projects.

We published our patches there https://code.launchpad.net/percona-patches, it is supposed to be main repository for the patches.

We advise to use Launchpad bug system to report bugs and also for feature requests.

Do you know that there are two limits about dirty (modified but not flushed to disk) blocks of InnoDB buffer pool? One is the limit of “amount”. The other is the limit of “age”.

– limit of “amount” –