Re. Explain (more is better?)

Myself, a number of the OLTP recommended settings proved to be badddd brett Dirk Moolman wrote: > > OPTCOMPIND = 0 proved to be VERY bad on our system, and we run OLTP. We > made some onconfig changes, but after changing OPTCOMPIND to 2, we had a > very drastic improvement in speed. > > Dirk > Reach Technologies > > -----Original Message----- > From: owner-informix-list@iiug.iiug.org > [mailto:owner-informix-list@iiug.iiug.org]On Behalf Of David Williams > Sent: Monday, December 11, 2000 3:59 AM > To: informix-list@iiug.org > Subject: Re: Explain (more is better?) > > In article <fApY5.29470$eT4.2358818@nnrp3.clara.net>, John Berry > <johnberry@clara.net> writes > >We have a large number of tables > 700 with a large majority in the range > >of > 1GB > > > >Some of the queries on the database can take a number of minutes especially > >when > >multiple joins are being performed. > > > >Now I have always assumed the lower the cost of query the better :-) > > > >However I am starting to doubt this when I run a low cost query on a > number > >of frequent hit tables it can take upto 2 mins to return data > >If I re-structure the query the cost goes up to 2500 but data is returned > in > >seconds ? > > > > Run you run the full update statistics? Perhaps the stat are out of > date. > > >Would I be right in assuming the cost is based on use of indexes and amount > >of data retrieved and not a lot else so a high cost query is not always > bad. > > > >and if so what about OPTCONF hmm 0,1 or 2 > > > > OPTCOMPIND = 0 favors indexes and should be used on OLTP systems. > > >:-) > > > > > > -- > David Williams -- ----------------------------------------------------------------- Brett's 10th law of UNIX administration... rm is forever ----------------------------------------------------------------- Brett Geer - UNIX Admin/Analyst/Programmer - Intratex Holdings. Tel. +27 31 717 4000 Direct. +27 31 717 4146 Fax. +27 31 717 4001 ----------------------------------------------------------------- The little voices are talking to me again, telling me to reach for a keyboard and type rm -rf /* last week they had me rm -rf `echo $MANPATH | sed 's/:/ /g'` now I fear I have no answers -----------------------------------------------------------------