Re: What ramifications are there for running two Instances on one host server.

Hi Fred: regrettably, I can't recommend anything along those lines (though I'm sure someone else will be able to do so). I work in the idealised world of teaching people how Oracle works *in principle*, and in principle, you shouldn't do it!!

I do sympathise, though. Oracle pricing is scary at best, and the temptation (and need) to skip on having multiple servers is correspondingly large. I suspect Jonathan Lewis might be your best source of advice on the potential pitfalls.

Regards
HJR "Fred Pierce" <fpierce_at_avialantic.com> wrote in message news:3A6ED437.3F6A1D4A_at_avialantic.com...
> Howard, can you recommend any good papers etc. on multi-instance server
> administration? Sometimes additional servers or consolidation aren't
> options (I've been struggling for three years to bring together myriad
> seperate projects each of which had their own instances for no good
> reason that I could discern except politics and ignorance). With CPU
> based pricing, I would expect management would be more inclined than
> ever to cram everything they can on one server.
>
> In some cases, such as incompatible application requirements, I would
> think it would be easier to tune seperate instances even if they are on
> the same server. I/O contention I can figure out but am uncertain about
> memory allocation, network traffic etc. Most of the tuning books in my
> collection (admittedly I haven't had time to dig deeply) seem to assume
> a monolithic operation where the DBA actually controls the configuration
> instead of "making do" with an inherited environment. There must be
> other "Balkanized" installations out there though, aren't there?
>
> fdp
>
> ---------------------------------------------------------
> Fred Pierce (DNRC) Gee I hope nobody from work reads this...
> www.Avialantic.com fpierce_at_avialantic.com
> MAAM World War II Weekend Airshow June 8-10 2001
> www.maam.org/maamwwii.html
> World Airshow News - www.wanews.com
> ---------------------------------------------------------
>
> "Howard J. Rogers" wrote:
> >
> > "toddthom" <orclnwsgrp_at_hotmail.com> wrote in message
> > news:94io0r$nru$1_at_nnrp1.deja.com...
> > > Hello Generous and All-Knowing,
> > >
> > > I'm a jdba and I'm currently involved in building an Operational Data
> > > Store and a Data Warehouse on one HPUX (11.0) N-Class server......two
> > > SID's one one node. We haven't actually built it yet, but, I thought
> > > Oracle's rule was a one to one relationship with regard to instance
 and
> > > database.....wouldn't this break the rule?
> >
> > It would only break it if you assume that a database is the same thing
 as a
> > node. The node is the HP Server -one physical box. The database is the
> > collection of controlfiles+datafiles+redo logs that relate to your Data
> > Warehouse, and the second database is the collection of
> > controlfiles+datafiles+redo logs that relate to your Operational
 Datastore.
> > Two databases, one node. Nothing wrong in that.
> >
> > You will have to have two Instances managing those two
 databases -because
> > the rule about 1 instance managing 1 database is always true (even in
> > Parallel Server). Two Instances, one node. Nothing wrong with that,
> > either.
> >
> > Except... that performance on either Instance will be affected by the
 work
> > being done on the other, and the i/o on one database will be affected by
 the
> > i/o on the other.
> >
> > So whilst there's nothing "wrong" with 2 or more databases and Instances
 on
> > one node, it's not normally recommended for performance reasons.
> >
> > >If not, what configuration
> > > recommendations would you make with regard to resources?
> > >
> >
> > Extremely tricky to suggest anything without knowing the loads and work
> > patterns for each database/instance. The simple (simplistic) advice is
 to
> > go buy another HP Server.
> >
> > Regards
> > HJR
> >
> > > Thanks
> > >
> > > Todd
> > > Peace
> > >
> > >
> > >
> > > Sent via Deja.com
> > > http://www.deja.com/
Received on Wed Jan 24 2001 - 14:25:03 CST