Using ALLTRIM() on idexes is a bad idea, the full field is always better and faster, because VFP does not have to preprocess the value for searching, for adding a new value and for reindexing.
El lun., 19 de marzo de 2018 23:29, Bill Anderson <billan...@gmail.com> escribió: > Mike, > > I believe ALLTRIM()s in SQL doesn't "defeat" optimization, it's just that > you can't have ragged (meaning, varying length) indexes in VFP. > > A tag on ALLTRIM(field) is padded out to the full length of the field. > > Bill Anderson > > > On Mon, Mar 19, 2018 at 12:55 PM, < > mbsoftwaresoluti...@mbsoftwaresolutions.com> wrote: > > > -----Original Message----- > >> From: ProFox [mailto:profox-boun...@leafe.com] On Behalf Of > >> mbsoftwaresoluti...@mbsoftwaresolutions.com > >> Sent: Sunday, March 18, 2018 2:34 PM > >> To: ProFox <profox@leafe.com> > >> Subject: Testing tells the tale (SYS 3054) -- "BETWEEN(a,b,c)" > >> equivalent to "a BETWEEN b and c" > >> > >> VFP9SP2 WestWind WebConnection App on WinServer 2012 > >> > >> I was looking at a notoriously slow query to see about optimizing it. > >> Using SYS(3054,11,"cmemvar"), I was able to do so, but during my > >> testing, I found that using MyDate BETWEEN Arg1 and Arg1 was the same > >> optimization-wise as BETWEEN(MyDate,Arg1,Arg2). Somewhere in history, > >> I thought that using VFP's native BETWEEN(field,d1,d2) was NOT > >> Rushmore friendly. However, testing with SYS(3054) showed otherwise! > >> > >> Just an interesting find this weekend for me whilst debugging. > >> > >> Carry on! > >> --Mike > >> > > > > > > Also found that the ALLTRIMs in some SQLs were defeating optimization as > > well. Just a tip for others here! I don't code that way but somebody in > > the history of this app did. > > [excessive quoting removed by server] _______________________________________________ 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/CAGQ_Juk36oB8Xes_pF5Ka3exCwLCHrsFF=ybqvi_oi+ym0i...@mail.gmail.com ** 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.