Yep, EXISTS will virtually always be faster, usually MUCH faster, than a correlated subquery, because a subquery is evaluated for EVERY ROW processed by the outer query.
On Wed, Aug 26, 2009 at 12:43 AM, Mark Henderson <shadefro...@gmail.com>wrote: > > Brian Kotek wrote: > > > > WHERE NOT EXISTS should also work. > > > > Yes it does, and I knew about that method when using NOT IN, as it was > a simple change to my original working query. What I didn't know, but > now do after some googling, is that NOT EXISTS means it uses an index > in the subquery as opposed to a full table scan (which was my primary > concern). Thanks Brian. > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| Want to reach the ColdFusion community with something they want? Let them know on the House of Fusion mailing lists Archive: http://www.houseoffusion.com/groups/cf-talk/message.cfm/messageid:325745 Subscription: http://www.houseoffusion.com/groups/cf-talk/subscribe.cfm Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=89.70.4
