I have not caused a fist fight in a while, so it’s time to take off the gloves. I claim that somewhere around of 99% of advice about tuning MySQL’s key cache hit ratio is wrong, even when you hear it from experts. There are two major problems with the key buffer hit ratio, and […]
I often see people confuse different ways MySQL can use indexing, getting wrong ideas on what query performance they should expect. There are 3 main ways how MySQL can use the indexes for query execution, which are not mutually exclusive, in fact some queries will use indexes for all 3 purposes listed here.
No, this is not about Sun and IBM This is about MySQL. If you download latest 5.1.33 source code you may find there storage/ibmdb2i directory, which obviously is IBM DB2 related. Interesting that there is no mentioning of new engine in Announcement http://dev.mysql.com/doc/refman/5.1/en/news-5-1-33.html. Quick look into source code says
MYSQL_STORAGE_ENGINE([ibmdb2i], , [IBM DB2 for i Storage Engine],
[IBM DB2 for i Storage Engine], [max,max-no-ndb])
Also interesting that license of […]
These days I’m working with a customer who has an application based entirely on stored routines on MySQL side. Even though I haven’t worked much with stored procedures, I though it’s going to be a piece of cake. In the end – it was, but there’s a catch.
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 […]
We were chatting with Jeremy Cole today and he brought to my attention last version of MySQL Community Eddition (5.0.51) was released in November 2007 – over 7 months ago. MySQL 5.0.51a and MySQL 5.0.51b security fixes were released but these can’t be considered proper releases. If we look at the old Kaj’s Announcement we […]
We were doing MySQL Performance evaluation on TPC-H queries for the client and they kindly allowed us to publish results which are very interesting. This is obviously not audited TPC-H run, and it can’t be because we used MyISAM tables which are not ACID complaint. Plus we only measured Power to keep things simple. We […]
Preparing to move I’m selling stuff on GumTree which is UK based clone of Craigslist offering similar functionality but with Ads Similarly to Craigslist GumTree is powered by MySQL but unlike craigslist it looks like they are shy in tuning their MySQL Full Text Search index configuration and setting proper ft_min_word_len value. Searching for Audi […]
One performance gotcha with MEMORY tables you might know about comes from the fact it is the only MySQL storage engine which defaults to HASH index type by default, instead of BTREE which makes indexes unusable for prefix matches or range lookups. This is however not performance gotcha I’m going to write about. There is […]
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 […]