Re: Why is NT/Oracle database so slow upon restarts?

Adrian schrieb:
>
> Youve gotta dig deeper than just relying on a beefy NT machine. Why is the
> system slow ? Is it CPU usage, network bottlenecks ? , disks being
> hammered...Thats quite a huge SGA you are running , it may well improve
> performance if you try and reduce it , check the performance guides for
> determining cache hit ratios by adding/reducing buffers , Are you taking
> full advantage of 4 CPU's ? Does Vantive use PQ's ? Can Vantive take
> advantage of new Oracle 8 features ? . You need to do some serious homework
> here. STart with the performance guide and make sure you feel happy that the
> system is well tuned...Try some of the discrete NT registry mods for
> improving NT's performance. Take care with RAID and be patient...
>
> skubiszewski_at_Eisner.DECUS.Org wrote in message ...
> >We're running a third-party application layered on top of Oracle7
> >on NT (Vantive.) The box is huge, 4 CPUs, 1.5 Gb RAM, NT 4/SP3
> >with Oracle v7.3.4 and about 40 connections during an average
> >workday. The SGA is sized at 1/3rd of physical memory.
> >
> >If the database is closed and reopened, it may take up to a
> >day of normal user activity to recover. I cannot figure out
> >why. I have pre_page_sga = true. No effect. It's slow in
> >the morning and better in the afternoon after a close & open.
> >
> >Because of this, users are reluctant to let me close the
> >database for cold backups. :-(
> >
> >Can anyone explain what is causing this? I do not see this
> >effect on our Unix Oracle7 database which is closed nightly
> >for cold backups.
> >
> >Rose

In addition to Adrian's posting, there may be some application related issue to look upon:

As you stated performance is better after some working hours, which is a sign that the most requested data is in the SGA and therefor can be provided in a very short time intervall. Try to provide data with insatce startup.

• are packages used => ping them into SGA on db-startup
• is data used by the application predictable (customer-data ASO) => ping the data into cache by issuing appropriate SQL-stats at db-startup

HTH
Matthias
--
grema_at_t-online.de

Protect privacy, boycott Intel: http://www.bigbrotherinside.org Received on Thu Mar 04 1999 - 02:51:57 CST