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 […]
Our customers or prospective customers often ask us how we do a performance audit (it’s our most popular service). I thought I should write a blog post that will both answer their question, so I can just reply “read all about it at this URL” and share our methodology with readers a little bit. This […]
Whilst working with a client recently I noticed a large number of temporary tables being created on disk.
show global status like 'Created_tmp%'
| Created_tmp_disk_tables | 91970 |
| Created_tmp_files | 19624 |
| Created_tmp_tables | 1617031 |
For a couple of months there have been no updates to our msl patch, however recently I managed some time to change this. The functionality was extended a little bit and whatâ€™s even more important the patch is available for all the recent MySQL releases. To remind anyone who has not yet come across this […]
Really often in customers’ application we can see a huge tables with varchar/char fields, with small sets of possible values. These are “state”, “gender”, “status”, “weapon_type”, etc, etc. Frequently we suggest to change such fields to use ENUM column type, but is it really necessary (from performance standpoint)? In this post I’d like to present […]
People are sometimes contacting me and asking about bugs like this which provide a trivial way to crash MySQL to the user with basic privileges and asking me what to do. My answer to them is – there is nothing new to it and they just sit should back and relax Really – there are […]
Microslow patch is used by many DBAs and developers to accurately time their queries and to catch those which run less than a second as they can also be a performance killer for a busy application. Recently I have started the development of an updated version of the patch. The basic idea is the same […]
My favorite question during Interview for people to work as MySQL DBAs or be involved with MySQL Performance in some way is to ask them what should be tuned in MySQL Server straight after installation, assuming it was installed with default settings. I’m surprised how many people fail to provide any reasonable answer to this […]
If you’ve been reading enough database related forums, mailing lists or blogs you probably heard complains about MySQL being unable to handle more than 1.000.000 (or select any other number) rows by some of the users. On other hand it is well known with customers like Google, Yahoo, LiveJournal,Technocarati MySQL has installations with many billions […]
MySQL Server has tons of variables which may be adjusted to change behavior or for performance purposes. They are documented in the manual as well as on new page Jay has created. Still I see constant confusion out where which of variables apply to storage engines only and which are used on SQL layer and […]