On 12/23/11 4:48 PM, Wade Preston Shearer wrote: > Am I correct in my understanding that the right side of an OR statement in an > MySQL query doesn't get evaluated unless the left side fails? I have a query > where the left-side case of an OR occurs often and produces an efficient > query and the right-side happens only occasionally and produces a slower, > less efficient query. If the query always checks both but only uses the left > if it is true, then I'd be better served to move it into two queries. If it > only checks the right-side condition if the left-side fails though, then > keeping it in one makes sense.
For queries like this you really need to check out the explain plan and see what mysql is doing with your select statement. This is one of the best ways to determine when mysql will use indexes or not on your data. -- thebigdog _______________________________________________ UPHPU mailing list [email protected] http://uphpu.org/mailman/listinfo/uphpu IRC: #uphpu on irc.freenode.net
