Today I took a look at some database performance tuning techniques, and I got a good series of articles about UDB performance tuning written by Roger Sanders in DB2 Magazine.
The links are:
Basic Performance Tuning, part 1
Basic Performance Tuning, part 2
Basic Performance Tuning, part 3
These 3 parts focus on tuning rules, system configuration and database design respectively, and the content is easy to read and comprehend.
Other sources include:
SQL Server Performance Tuning in SQL-Server-Performance.Com
Database Administration with Weblogic , which I believe focuses on the application design domain. (didn't read it yet)
PostgreSQL Performance Tuning, I'm a little bit familiar with it.
Another Performance Tuning of PostgreSQL, everybody likes free products!
SQL Performance Tuning Using Indexes , it seems that the author has a misunderstanding between clustered index and integrated index. Or maybe it's a product-specific issue.
Best Practice for Tuning DB2 UDBv8.1 in IBM Developer Networks.
Getting Started with DB2 Application Tuning, it contains some sources for other technical papers.
IBM Information Management Products Training
Oracle Database Site
Oracle 9i Documentation collected by Leiden University