I was just throwing out some options that came off the top of my head. There was no real thought put into optimizing beyond general rushmore rules.
Do you really need the DISTINCT when the GROUP BY is there? My understanding, at least as far as VFP SQL is concerned, is that DISTINCT will force a table scan whereas GROUP BY is rushmore optimizable and will use an available index tag. And as Uncle Ted would say, none of this theoretical stuff matters. You have to test with your data to know your stuff is optimized in your environment. :-) -- rk -----Original Message----- From: ProfoxTech [mailto:profoxtech-boun...@leafe.com] On Behalf Of Dave Crozier Sent: Wednesday, April 16, 2014 11:33 AM To: profoxt...@leafe.com Subject: RE: SQL Query Richard.... More efficient this way if there ate multiple instance records in the compno field Select columns from table Where compno not in (select distinct compno from table Where compno='value1' or compno='value2' or... Group by compno) Dave _______________________________________________ Post Messages to: ProFox@leafe.com Subscription Maintenance: http://mail.leafe.com/mailman/listinfo/profox OT-free version of this list: http://mail.leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/DF1EEF11E586A64FB54A97F22A8BD04422A746027B@ACKBWDDQH1.artfact.local ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
