MySQL supports two different algorithms for views: the MERGE algorithm and the TEMPTABLE algorithm. These two algorithms differ greatly. A view which uses the MERGE algorithm can merge filter conditions into the view query itself. This has significant performance advantages over TEMPTABLE views. A view which uses the TEMPTABLE algorithm will have to compute the [...]
MySQL VIEW as performance troublemaker
August 12, 2007 By 55 Comments
I start to see applications being built utilizing VIEWs functionality which appeared in MySQL 5.0 and quite frequently VIEWs are used to help in writing the queries – to keep queries simple without really thinking how it affects server performance. Even worse than that – looking at the short table which just gets single row [...]
Derived Tables and Views Performance
August 31, 2006 By 15 Comments
Starting MySQL 4.1, MySQL had support for what is called derived tables, inline views or basically subselects in the from clause. In MySQL 5.0 support for views was added. These features are quite related to each other but how do they compare in terms of performance ?
Database problems in MySQL/PHP Applications
August 11, 2006 By 13 Comments
Article about database design problems is being discussed by Kristian. Both article itself and responce cause mixed feellings so I decided it is worth commenting: 1. Using mysql_* functions directly This is probably bad but I do not like solutions proposed by original article ether. PEAR is slow as well as other complex conectors. I [...]
MySQL EXPLAIN limits and errors.
July 24, 2006 By 6 Comments
Running EXPLAIN for problematic queries is very powerful tool for MySQL Performance optimization. If you’ve been using this tool a lot you probably noticed it is not always provide adequate information. Here is list of things you may wish to watch out. EXPLAIN can be wrong – this does not happen very often but it [...]
