Re: Basic Oracle Concepts

From: DA Morgan <damorgan_at_psoug.org>
Date: Thu, 28 Jul 2005 08:51:49 -0700
Message-ID: <1122565876.63097@yasure>

Paul wrote:
>
> DA Morgan <damorgan_at_psoug.org> wrote:
>
>
>

>>The Oracle program code, executing in memory, is an Instance. And
>>multiple instances can connect to a single database. This is what is
>>referred to as RAC (Real Application Clusters).

>
> I've been reading up on the Concepts Guide and am a little unclear.
>
> One can also have one Instance connected to multiple databases?

No.

For
> example, if on my machine, there were users connected to both the
> SCOTT and HR schemas (at the same time), or even one user connected to
> both at the same time (and say both were running long running queries
> concurrently).
>
> Or is that two Instances on one machine?
>
>
>
> Paul...

An end user can only connect to one schema in one database using the processes of one instance at a time. No exceptions.

SCOTT and HR are different schemas and you can only connect to one. From that one you can access objects owned by another provided you have been granted appropriate object privileges. Otherwise you can not even know the other one exists.

-- 
Daniel A. Morgan
http://www.psoug.org
damorgan_at_x.washington.edu
(replace x with u to respond)

Received on Thu Jul 28 2005 - 10:51:49 CDT