Re: IN vs EXISTS - which is better?

>> Does anybody know if this is true? <<

It depends.  Older versions of DB2 used to use indexes for EXISTS()
predicates and they were quite a bit faster than the IN() predicate
that mateiralized a temp table on the fly.  Since a myth was born. 
These days, a good optimizer will find the best way regardless of the
predicate.  I'd say use the one which is easier to read, unless you
find a real difference by testing both.