Jim Dettman
jimdettman at earthlink.net
Wed Aug 13 15:30:02 CDT 2003
Mark, That's a good question and I don't believe anyone outside of Microsoft knows the answer. Intersections between indexes is a Rushmore optimization, which has never been documented. I do know that for a compound index, the search fields must be in the same order as the index or it is not used. SHOWPLAN on the query might give you some idea what it's doing, but it would be still conjecture as to what's really happening on the search. I suppose a little testing on a rather large recordset would yield an answer. Jim Dettman President, Online Computer Services of WNY, Inc. (315) 699-3443 jimdettman at earthlink.net -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com]On Behalf Of Mark Whittinghill Sent: Wednesday, August 13, 2003 2:33 PM To: accessd at databaseadvisors.com Subject: [AccessD] Indexes on text fields Let's say I have a Person table with FirstName and LastName fields. Both are non-unique indexed to help searches. Now say I build a query with a concatenated field FullName: LastName & ", " & FirstName. Will the indexes on these fields help speed searches on the FullName field? Mark Whittinghill Symphony Information Services 612-333-1311 mwhittinghill at symphonyinfo.com _______________________________________________ AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com