Re: Index & Optimizer question

UPDATE STATISTICS Try it for this table, Octav On Thu, May 27, 1999 at 02:49:41PM +0300, Vic Matskiv wrote: > Hi, all! > I've got some problems with perfomance on my OnLine 7.20/SCO OpenServer > because > When I create the non-unique index on table T by field F and then > try to execute: > set explain on; > select * from T where F=10000;> I get the SEQUENTIAL SCAN by field F (in log file)!!! > Why doesn't the optimizer use corresponding index ??? > > Thanks indeed :) > > > > -- Octav Chiriac Phone: (373) 2 21 20 96 NetInfo S.R.L. Fax: (373) 2 21 36 59 Chisinau (373) 2 24 00 83 Moldova, Republic of mailto:com@netinfo-moldova.com

Octav Chiriac wrote: > > UPDATE STATISTICS> > Try it for this table, > Octav sorry, i think, informix uses the indexes depending on the actual weather or sunshine or so on :( in our application, i must execute an UPDATE STATISTICS on some tables, on other tables i have to... DROP DISTRIBUIONS to get the right indexes work. but these is various from dbase to dbase and version to version (currently 7.1x to 7.3x) (depending on the actual...) > On Thu, May 27, 1999 at 02:49:41PM +0300, Vic Matskiv wrote: > > Hi, all! > > I've got some problems with perfomance on my OnLine 7.20/SCO OpenServer > > because > > When I create the non-unique index on table T by field F and then > > try to execute: > > set explain on; > > select * from T where F=10000;> > I get the SEQUENTIAL SCAN by field F (in log file)!!! > > Why doesn't the optimizer use corresponding index ??? > > > > Thanks indeed :) -- Klaus Thiele - Personal & Informatik AG mailto:kth@piag.com "There's got to be more to life than compile-and-go."