Re: multiple schema or multiple instance

see_at_reply-to.invalid (Bruno Jargot) wrote in message news:<1gky82b.es64cr1v2h3uoN%see_at_reply-to.invalid>...
> Hello,
>
> I would like to understand when it's better to have multiple schema and
> when it's better to have multiple instance.
> By reading this group, I feel I'm missing something...
>
> Having multiple schema in one instance allow a far better utilization of
> the resource (RAM, disk) of the server. And it's more simple for
> administrative task.
> Having multiple instance allow an independance between the applications.
> Independance for the parameters of the database, independance for the
> shutdown of the instance.
>
> But the key point is the restore of the database. If a schema require a
> incomplete recovery, all the database will be concerned by this
> incomplete recovery and it would not be acceptable for the other
> application using the other schema.

To add a bit to what Kenneth said, this used to be more-or-less true, but the more "recent" work-arounds include being able to backup by tablespace. And many of the older tech apps could be dealt with with export/import. What I see is that the separate instances are required due to recovery issues are development and test.

Larger apps and budgetary reasons sometimes mean separate instances on separate boxes. And of course, development and test should be separate, too.

>
> So, for production database, one instance for one application is almost
> always required. Do you agree or do I miss something ?

You miss the "new features."

jg

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