As Calpont announced availability of InfiniDB I surely couldn’t miss a chance to compare it with previously tested databases in the same environment. See my previous posts on this topic: Analyzing air traffic performance with InfoBright and MonetDB Air traffic queries in LucidDB I could not run all queries against InfiniDB and I met some [...]
Rendundant Array of Inexpensive Servers
August 21, 2008 By 15 Comments
So you need to design highly available MySQL powered system… how do you approach that ? Too often I see the question is approached by focusing on expensive hardware which in theory should be reliable. And this really can work quite well for small systems. It is my experience – with quality commodity hardware (Dell,HP,IBM [...]
Updated msl (microslow) patch, installation walk-through!
April 20, 2008 By 17 Comments
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 what’s even more important the patch is available for all the recent MySQL releases. To remind anyone who has not yet come across this [...]
Managing Slave Lag with MySQL Replication
October 12, 2007 By 15 Comments
The question I often get is how far MySQL may fall behind and how to keep replication from lagging. The lag you will see will vary a lot from application to the application and from load to load. Plus what is the most important within same application the lag will likely have spikes – most [...]
MySQL Consulting – Being on your own
February 20, 2007 By 7 Comments
About half a year have passed since me and Vadim have left MySQL to do MySQL Consulting on our own. Bunch of people have been wondering about our experiences so I thought it would be worth to share it here.
Using LoadAvg for Performance Optimization
December 4, 2006 By 5 Comments
Linux and Unixes have excellent metric of system load called “loadavg”. In fact load average is is 3 numbers which correspond to “load average” calculated for one five and 15 minutes. It is computed as exponential moving average so most recent load have more weight in the value than old one. What does Load Average [...]
MySQL: Followup on UNION for query optimization, Query profiling
August 14, 2006 By 14 Comments
Few days ago I wrote an article about using UNION to implement loose index scan. First I should mention double IN also works same way so you do not have to use the union. So changing query to:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | mysql> SELECT sql_no_cache name FROM people WHERE age in(18,19,20) AND zip IN (12345,12346, 12347); +----------------------------------+ | name | +----------------------------------+ | ed4481336eb9adca222fd404fa15658e | | 888ba838661aff00bbbce114a2a22423 | +----------------------------------+ 2 rows in set (0.00 sec) mysql> explain SELECT sql_no_cache name FROM people WHERE age in(18,19,20) AND zip IN (12345,12346, 12347); +----+-------------+--------+-------+---------------+------+---------+------+------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+--------+-------+---------------+------+---------+------+------+-------------+ | 1 | SIMPLE | people | range | age | age | 4 | NULL | 9 | Using where | +----+-------------+--------+-------+---------------+------+---------+------+------+-------------+ 1 row in set (0.00 sec) |
So as you see there are really different types of ranges in MySQL. IN range allows [...]
How Web Services world affect LAMP Stack
May 22, 2006 By 1 Comment
In connection to my previous post I was thinking how Web 2.0 with its massive use of Web Services affect LAMP Stack ? Well actually there are serious difference both for client and server application development which you might want to take into account. If you’re developing Web Service Server application you will most likely [...]
MySQL Server Memory Usage
May 17, 2006 By 21 Comments
Every so often people ask me the question how should they estimate memory consumption by MySQL Server in given configuration. What is the formula they could use. The reasons to worry about memory usage are quite understandable. If you configure MySQL Server so it uses too small amount of memory it will likey perform suboptimally. [...]
