Re: bad performance with a simple select statement
Another idea - have you tried running "update statistics" on this table yet
?
Gursoy YERLI <gursoy@ata.net> wrote in article
<6ugrue$i7t$1@news.xmission.com>...
>
> Keep in mind that activating PDQ (Parallel Database Query) parameter
forces
> informix to do sequential scan with hash join. Of course before turning
the
> PDQ parameter off (if activated), try other advises.
>
> Gursoy YERLI
>
> lol007@my-dejanews.com wrote:
>
> > Hello:
> > I run INFORMIX-Universal Server Version 9.14.UC1X3 on a SGI/IRIX 6.2
INDY
> > RS5000SC box.
> > I create a buffered-logging database in a mirrored dbspace.
> > I create the following table :
> > create table test (
> > f1 int,
> > f2 smallfloat,
> > f3 smallfloat,
> > f4 smallfloat,
> > f5 smallfloat,
> > f6 smallfloat,
> > f7 smallfloat,
> > f8 smallfloat,
> > f9 smallfloat,
> > f10 smallfloat,
> > PRIMARY KEY (f1)
> > );> > I load the table with a 400K records file.
> > The following simple statement :
> > select * from test where f1=200000;> > takes 10 seconds !?
> >
> > I even tried the following :
> > begin work;
> > set isolation to dirty read;> > select {+ USE_INDEX(test,100_1) } * from test where f1=1;
> > commit work;
> > Still 10" long !
> >
> > The same query on MS SQL 6.5 is almost instantaneous ... :-(
> >
> > Any idea ?
> > LL
> >
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