Joyeur: Quick wins with MySQL
performance tips fro mysql
assert_efficient_sql - O'Reilly Ruby
rails plugin that can detect inefficient queries in test cases
MySQL :: A Quick Look at MySQL 5.4
info on some nice changes coming in MySQL 5.4, particuarly subquery optimisations
More on Postgres Performance - Craig Kerstiens
The Guide To Understanding mysqlreport
Configuring sql.DB for Better Performance - Alex Edwards
how to control the connection pool in database/sql