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.
MySQL random freezes could be the query cache
March 19, 2009 By 23 Comments
I feel like I’ve been seeing this a lot lately. occasionally, seemingly innocuous selects take unacceptably long. Or Over the past few weeks, we’ve been having bizarre outages during which everything seems to grind to a halt… and then fixes itself within 5 minutes. We’ve got plenty of memory, we’re not running into swap, and [...]
High-Performance Click Analysis with MySQL
December 22, 2008 By 13 Comments
We have a lot of customers who do click analysis, site analytics, search engine marketing, online advertising, user behavior analysis, and many similar types of work. The first thing these have in common is that they’re generally some kind of loggable event. The next characteristic of a lot of these systems (real or planned) is [...]
How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
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 [...]
Living with backups
November 6, 2008 By 28 Comments
Everyone does backups. Usually it’s some nightly batch job that just dumps all MySQL tables into a text file or ordinarily copies the binary files from the data directory to a safe location. Obviously both ways involve much more complex operations than it would seem by my last sentence, but it is not important right [...]
Should you have your swap file enabled while running MySQL ?
April 6, 2008 By 31 Comments
So you’re running dedicated MySQL Linux box with plenty of memory, so the good question arises if you should have swap file enabled or disable it ? I’ve seen production successfully running on boxes both with and without swap file so it is not the question of you must do it this or that way [...]
The tool I’ve been waiting for years
March 18, 2008 By 10 Comments
I’ve just been pointed to the nice tool which I was waiting for years to see. It is fincore – little perl script which allows you to see what pages of file are cached in OS memory. This is really cool.
Economics of Performance Optimization
March 13, 2008 By 9 Comments
I think every person responsible for Development or Operations of growing application sooner or later have to decide on couple few questions on how to tackle application performance. These questions are: Should we Optimize Application or get more Hardware ? Should we do things ourselves or hire an experts to help us ? The answer [...]
Choosing innodb_buffer_pool_size
November 3, 2007 By 39 Comments
My last post about Innodb Performance Optimization got a lot of comments choosing proper innodb_buffer_pool_size and indeed I oversimplified things a bit too much, so let me write a bit better description. Innodb Buffer Pool is by far the most important option for Innodb Performance and it must be set correctly. I’ve seen a lot [...]
InnoDB in self-compiled MySQL 5.1
September 13, 2007 By 9 Comments
If you like to compile MySQL from sources by yourself, for different needs, like debugging, testing etc, you probably can face this issue. What I usually do to fast compile and test is
1 2 3 | ./configure --prefix=/dir/to/mysql make make install |
and then, for example, load the dump of InnoDB from previous version:
1 | mysql testdatabase < dump.sql |
I bet you will not notice all your [...]
