Re: Bad Performance after Upgrades

As "Informix" grows... they make ever so slight (sometimes not) changes. Many versions ago, you could just write your code with no PREPARE statement: delete from <table_name> where a = b and c = d and e = f (same thing with "update" In changing from 7.24 to 7.3x you may find that when running the sql above, onlt the a= b part will be used to delete (or update) as the case may be. We ran many test between 7.24 (and 7.22) against 7.3x. Yes, we were getting very different timings... and when we compared file sizes of the final unloads, again their was a HUGH difference. It turned out, where programmers before had not used the PREPARE statement, in 7.3x they need to. The offending code was placed into the PREPARE and the timing and unload file sizes when back to normal. Point... never believe blindly, ALWAYS TEST first. > > You might also want to check your code... > > > > 7.31 requires greater useage of PREPARE statements > > then 7.24 did. > >Jim, > >please elaborate on that statement. What code do you mean? 4GL, >ESQL/C or what? Why should statements have to be PREPAREd with >version 7.31 of the server which worked just fine in 7.24? > >What could be the case is that Stored Procedures have to be >recompiled with the new server version. > >Regards, Richard >-- >+-----------------------------+-------------------------------------+ >| Dr. med Richard Spitz | Mail: spitz@ana.med.uni-muenchen.de | >| Klinik f'r Anaesthesiologie | Tel : +49-89-7095-6110 | >| Klinikum der Univ. M'nchen | FAX : +49-89-7095-6420 | >| 81366 M'nchen, Germany | GSM : +49-172-8933578 | >+-----------------------------+-------------------------------------+ ________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com

jim lowry wrote: > Many versions ago, you could just write > your code with no PREPARE statement: > > delete from <table_name> > where a = b > and c = d > and e = f > > (same thing with "update" What were you writing this code in? ESQL/C? 4GL? Shell-Scripts? > In changing from 7.24 to 7.3x > you may find that when running > the sql above, onlt the a= b > part will be used to delete (or update) > as the case may be. This still doesn't make sense to me. We went from Online 5.10 to IDS 7.30 (currently 7.31UC4) and NEVER experienced anything like the trouble you describe. There are dozens of 4GL and ESQL/C programs running against the server, along with numerous SQL scripts run by dbaccess or isql. > Point... never believe blindly, ALWAYS TEST first. I'd love to reproduce what you describe, but you have to give me some more information and/or sample code. Regards, Richard -- +-----------------------------+-------------------------------------+ | Dr. med Richard Spitz | Mail: spitz@ana.med.uni-muenchen.de | | Klinik für Anaesthesiologie | Tel : +49-89-7095-6110 | | Klinikum der Univ. München | FAX : +49-89-7095-6420 | | 81366 München, Germany | GSM : +49-172-8933578 | +-----------------------------+-------------------------------------+