Re: Schema/Users relationship

On 13 Oct 2002 03:47:34 -0700, balan_tudor_at_yahoo.com (Tudor) wrote:

>Hi all,
>
>I am new to oracle and i have just read the documentation from Oracle
>8i concepts about the fundamental concepts. However, i have some
>questions and i really hope that some one could give me some more
>clear definitions and answers to my questions:
>
>1) I've read in the documentation that for each user of a database
>there is an associated schema(with the same name). But running the
>following sqls :
> --select username from dba_users order by username;
> --select distinct owner from dba_objects;
>i discovered that it is possible to have some users without a schema.
>Som the oracle documentation is false?? Furthermore, i read on this
>discusion group an answer to a question claiming that "there
>definitely will be users without a schema". SO, PLEASE SOMEBODY CLEAR
>ONCE FOR EVER THIS PROBLEM FOR ME.
>
>2) Is is possible to allow a user A to access the tables of a user B's
>schema?
>
>Thank you in advance
>
>Tudor

1. This depends on how you define schema: in the 3-layer architecture you have conceptual, logical and physical schemas. If you understand a schema as a conceptual schema every user will have a schema, because every user will have access to (part) of the database. However, the create schema command (which does exist, but no one uses it) specifically is implementing objects with a physical representation: so tables, indexes, clusters and the like. If you understand schema in this fashion there definitely will be users without their own objects, so without a schema.

2 Yes, this is possible. User B needs to grant privilige to user A to allow this.

Hth

Sybrand Bakker, Senior Oracle DBA

To reply remove -verwijderdit from my e-mail address Received on Sun Oct 13 2002 - 06:02:52 CDT