Fw: 7.30 -> 9.20 Anyone remember this?

["Vasyl Shulzhenko" <vasilis@softline.kiev.ua>]

----- Original Message -----
From: Rudy Fernandes <rferdy@americasm01.nt.com>
Newsgroups: comp.databases.informix
Sent: 30 ЛЮЪ 2000 Ц. 23:36
Subject: Re: 7.30 -> 9.20 Anyone remember this?


> I've been testing performance of v9.20 against that of v7.31, with both
> versions running on the same machine, though not concurrently. In general,
> performance of v9.20 is better than or equal to that of v7.31.
>
> However, my testing is targeted at OLTP operations. Maybe, the optimizer
in
> v9.20 is working differently, using an inefficient path to execute your
DSS
> query.
>
> Check if the "explained" method for executing the query differs. If it
> does, use directives to force v9.20 to take the v7.30 path.  If
performance
> is now comparable, the Optimizer is to "blame".
>
> If the Optimizer is behaving, check "onstat -p" stats after running the
> query on either instance (make sure you have initialized stats [ onstat -z
> ] first). If usercpu is vastly different, then there is some problem with
> the v9.20 Instance configuration (BUFFERS, possibly).
>
> If usercpu on the 2 instances are approximately the same, then something
at
> the OS level is inhibiting your v9.20 instance (disks, most likely).
>
> Let us know what you find.
> Rudy
>
> dmoeller@geocities.com wrote:
>
> > Hey all,
> >
> > I have an existing 7.30.UC2 database where I run a large join query
> > (building a big fact table).  I installed 9.20.UC2 into another
> > different INFORMIXDIR and dumped the schema from the 7.30 instance and
> > loaded up into the 9.20 instance for all the tables.
> >
> > I then setup connectivity between the instances and copied the data over
> > with select's.
> >
> > The problem is when I run the same large join query in the 9.20
> > instance performance is terrible.  200 rows per second vs. 3000 rows a
> > second for the 7.30 instance.
> >
> > ...Thanks,
> >
> > Dave
> >
> > Sent via Deja.com http://www.deja.com/
> > Before you buy.
>