Re: Oracle base

"David E. Grove" <david_grove_at_correct.state.ak.us> schrieb im Newsbeitrag news:10se3el3tan8nee_at_corp.supernews.com...
> OK, I thought I had the Oracle terminology figured out, but, based on this
> reply, I now think I was mistaken.
>
> By "instance", we mean the processes, the Oracle software, right?
No.
The processes and the software are two different things. the same software (the same files on disk) can run twice and access different sets of data and configuration files. In that case you have two instances, i.e. two sets of processes.

> So, if we
> want to have multiple instances of Oracle, we necessarily need multiple home
> directories, right?

No. See above.

> One home for each instance (i.e., for each installation
> of Oracle software). Now, each instance can have only a single database,
> right? But, a particular database can be used by multiple instances, is
> THAT correct? Do I have it now?

Unless you use RAC, one database (i.e. bunch of data files, redo logs etc.) can be managed and accessed by one instance only at any given point in time.

> I had been under the impression (erroneously, now, I believe) that there was
> necessarily a 1:1 relationship between instance and database.
Have you had a look at the "database concepts" documentation? Mount your doc cd, attach the index (a .pdx file) to acrobat reader and do a full text search for "database concepts". It should have a glossary where the terms "database" and "instance" are explained.

Lots of Greetings!
Volker Received on Mon Dec 20 2004 - 12:04:59 CST