doubt on rollback segment
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Thread: doubt on rollback segment

  1. #1
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    doubt on rollback segment

    Hi..
    I'm new to dba.i've a doubt on rollback segment..oracle guru's kindly help me..
    Here'z the doubt..
    Any DML statements(insert,update,delete) made to any table in the database has a rollback entry..
    But even a create tablespace command(which is a DDL) updates the sys owned table 'ts$' in data dictionary. why there are no rollback entries from 'create tablespace' command.??

    kindly help..

    Rgds,
    Sarav
    saravana kumar

  2. #2
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    who says there arent?

  3. #3
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    Hi

    rollback segmenst is used when i want to read consistency..

    when you create a tablespace (DDL) ----raed consistency is not requied


    when you do a ddl like this...

    create table xyz
    as
    select * from emp --------------This requires read consistancy

    hence eevnthough the second is a DDL it uses rollback because the select part has to eb done in read consistent mode..

    when you do such opeartion ts$..they are logged in the redologs..not the rollback..

    regards
    Hrishy

  4. #4
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    But pando..i've only studied that only dml statements will have rollback entries..thatz why you can rollback.
    but,since ddl statements dont have a rollback entries,they cannot be rolled back.

    Rgds,
    sarav
    saravana kumar

  5. #5
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    well

    imagine you have to alter a 100000 millions of table, alter is DDL, what happens if during your alter the databse dies? you cannot rollback but Oracle can
    Last edited by pando; 05-16-2003 at 07:31 AM.

  6. #6
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    hey..ur answer sounds good.but can u give me a perfect answer.
    tell me what happens when u give a ddl(create,alter,drop) and when you give an dml(insert,update,delete).
    will there be rollback entries generated for the dml and ddl comands?

    rgds,
    sarav
    saravana kumar

  7. #7
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    dont know what are you talking about

  8. #8
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    Originally posted by ksarav
    hey..ur answer sounds good.but can u give me a perfect answer.
    tell me what happens when u give a ddl(create,alter,drop) and when you give an dml(insert,update,delete).
    will there be rollback entries generated for the dml and ddl comands?

    rgds,
    sarav
    Read this...

    http://asktom.oracle.com/pls/ask/f?p...2860243091362,
    Amar
    "There is a difference between knowing the path and walking the path."

    Amar's Blog  Get Firefox!

  9. #9
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    thanks for that article..it was really great..

    thanks adewri..

    rgds,
    sarav
    saravana kumar

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