I still see SQL “performance tuning” that consists of random hints, superstition, bad indexing, voodoo, and parameter hacking, all applied with complete confidence and limited understanding. It’s not tuning. It’s hope.

Performance Tuning is not an art. It's not magic. It is the logical application of mathematical rules for deterministic outcomes.

Lets dissect Performance Tuning and see what happens in the real world as we try to avoid unintended consequences and look at what you really need to do for effective Performance Tuning.