Re: URGENT! How many rows will be returned?

I smell a troll here... Different databases use different technologies for query optimization and some are far better than others. Some 'so-called' optimizers need subtle hints to steer queries while others produce cost estimates based on statistics. Each database on your cross posting *frown* will do query optimization in different ways. There is no standard way of doing it, and besides, each commercial database vendor keeps its query optimization technology a closely guarded secret. You could start your search for Nirvana (let's face it I'd love to write queries that gave accurate answers without actually touching the data) by reading up on database system catalogs. Good luck.