Re: multiple databases

Yasaswi Pulavarti wrote:
> Hans:
> Howard Rogers in the earlier post clarified all my questions. However
> I did want to get back to you. What I mean by a database is a
> "collection of tables" that span over multiple tablespaces.

We call that a schema.

>You are
> right about different vendors treating databases differently. In DB2
> for example you can have one Instance and have many databases in that
> one instance.
> However I guess in Oracle, Instance and Database mean the same

Eeek! Not likely!! An instance is a memory structure. A database is a collection of physical files. I can have the one without the other. If I don't say startup, I have the files (database) but no memory structures (instance). If I say startup nomount, I have the memory structures without necessarily having the physical files (guess what state you have to be in to say "create database").

>or in
> other words one instance can have only one database.

Absolutely 10000% true. However, a database can be opened and manaaged by many instances. We call that a Real Application Cluster. And aspirins are available from your nearest pharmacy!!

Regards
HJR
> Thanks,
> Yasaswi
>
> HansF <news.hans_at_telus.net> wrote in message news:<sgnmd.178895$9b.74522_at_edtnps84>...
>
>>Yasaswi Pulavarti wrote:
>>
>>
>>>In one SID or instance can I create three different databases? Or does
>>>the term "Single Instance Database" (SID) mean only one database per
>>>instance? Also other than using the dbca (Database Congifuration
>>>Assistant) GUI utility, and other than just running a script, is there
>>>a way to create databases? Is there a text based interactive utility
>>>to create databases in Oracle?
>>>Thanks,
>>>Yasaswi
>>
>>Please explain what you mean by database.
>>
>>Oracle has a specific definition. Other RDBMS vendors also have definitions
>>but they are different from Oracle's (and each other's). The difference in
>>definitions leads to a lot of confusion.
>>
>>No matter what definition you use, Oracle does not have an interactive
>>command line utility to prompt you through database creation. Ultimately
>>all you have is a script, and DBCA simply creates and runs the 'script'.
>>
>>Please exlpain what you are trying to accomplish (the business reason) so we
>>can think of alternates that might help.
>>
>>/Hans
Received on Wed Nov 17 2004 - 03:41:56 CST