Re: database, tablespace, user confusion

On 28 Aug 2003 05:07:26 -0700, tridentadm_at_netscape.net (DukeNM) wrote:

>i am newbie to oracle dba. (and even oracle i guess)
>
>but anyways comming to the point...
>i am getting a little bit confused on
>create user
>create tablespace
>create database
>
>if a tablespace is logical specification of physical datafiles
>

I think you're looking through the wrong end of the telescope. A tablespace is a logical structure that is implemented within one or more physical files. A tablespace may be associated with one or more files, but a file can be associated with only one tablespace.

In other words, a file (or collection of files) contain the logical structure known as a "tablespace." A single tablespace may be contained within multiple files, but any given file can contain only one (or a part of one) tablespace.

>what does database do??

It manages data . . .

Which even though that's what you asked, I suspect is not what you meant. ;-)

A database is a logical entity made up of multiple tablespaces (see above) as well as several other files that are not related to tablespaces. In addition, there are the executing processes and memory structures (an "instance") that are sometimes loosely thought of as being part of the database.

This is Oracle's meaning of the word "database." In SQL-Server, the word "database" means something entirely different. In that system "database" refers to the collection of objects (tables, indexes, etc.) that belong to a given username. In Oracle, this is called a "schema."

HTH Received on Thu Aug 28 2003 - 09:15:27 CDT