What was your coolest SQL optimization, on a slow performing query?

Question

Just speaking to a colleague of mine. He was walking with a hop in his step, on the way to the coffee machine.

I asked him \"what\'s with the \'swarmy\' walk?\", he said

Answer 1

It's always nice to take a poorly written, cursor-laden query and eliminate cursors, cut the code by half, and improve performance many-fold.

Some of the best improvements are in clarity (and often result in nice performance boosts, too).