difference between schema and user
DBAsupport.com Forums - Powered by vBulletin
Results 1 to 7 of 7

Thread: difference between schema and user

  1. #1
    Join Date
    Oct 2000
    Posts
    139
    Hi

    I am quite confused of the concept of schema and user, it seems to me that they are both the same... can anyone explain a bit?

  2. #2
    Join Date
    Sep 2000
    Posts
    155

    Both are one and the same.

    Schema is a logical term that is defined as the
    collection of all the objects (tables, indexes, triggers procedures, sequences, etc) owned by a particular user.


  3. #3
    Join Date
    Oct 2000
    Posts
    139
    Hi

    I dunno if this is correct what I understand these two terms are as follows

    schema are objects owned by an user
    however an user can access several schemas if enoguh privilege are granted to them

    but people tells me that all objects that an user can access forms a schema

    so what it confuses me is that

    a schema forms the group of objects that an user can access including objects not created by the user

    or

    a schema are only those objects that are created by an user?

  4. #4
    Join Date
    Feb 2000
    Location
    Washington DC
    Posts
    1,843
    sweetie,

    By any chance you have Enterprise Manager. If you open DBA studio and select schema view 'by object' and 'by schema' you can see the difference with your eyes. Even if you don't have OEM set up for your enterprise, you can set up OEM client on your terminal and login locallly without Management server.

    AFIK, Schema can be mentioned in terms of 'Ownership'. Unless otherwise the user creates objects, user can't be owner of those objects. User might be having equivalent permissions of Owner(select,insert,update,delete) on other's objects, he can't be owner of objects.

    So, to my understanding:

    schemas are collection of objects that are created by an user?

    NOT

    schema forms the group of objects that an user can access including objects not created by the user.







  5. #5
    Join Date
    Nov 2000
    Location
    Baltimore, MD USA
    Posts
    1,339
    True, as far as Oracle is concerned.

    The confusion probably stems from the fact that Oracle did not invent the term 'Schema', AFAIK. And if they did, it has since been twisted.

    From the application side of the house, the database schema is the same as the model is the same as the set of objects that the application uses, whether that is through views, tables or synonyms, regardless of who owns them. Furthermore, when I log into the application as a user, the schema is 'what I can see' as a user, which can be different from the application's definition of the 'schema' and different still from the database's definition of the schema.

    From Oracle's perspective, the term 'schema' is as sreddy defined it, AKAIK, the set of objects actually created by ( or owned by) a given user.

    HTH,

    - Chris

  6. #6
    Join Date
    Jul 2000
    Posts
    296
    Strictly a schema is the set of objects owned by a user, as rpardip defined.
    With the right privileges a user can create objects in another users schema.

  7. #7
    Join Date
    Feb 2000
    Location
    Washington DC
    Posts
    1,843
    Well! Thats what Chris talking about. Its not specific definition. From application perspective its different, Database perspective diffrent. We use often in conversation in different contexts diffrently.

    From DBA perspective, If I can't see other user objects under that schema, I don't call it is part of the schema where as application can see it and from application perspective, Hence its called schema(your definition) as it includes other's objects too.





    [Edited by sreddy on 01-25-2001 at 09:25 PM]

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  


Click Here to Expand Forum to Full Width