http://qs321.pair.com?node_id=512599


in reply to (OT) Don't blow that index dude.

been there, done that =)

i find the EXPLAIN function in mysql extremely helpful as it can show you which index it will use.
also, with USING (indexname) you can force mysql to use a specific index if it isn't clever enough to find it out by itself. don't know, which DBMS you're working on.