Maximum undo_retention value for automatic undo_management
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Thread: Maximum undo_retention value for automatic undo_management

  1. #1
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    Maximum undo_retention value for automatic undo_management

    Does anyone know the maximum undo_retention value for automatic undo management?
    OCP 8i DBA

  2. #2
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    I did RTFM and it says

    Range of values
    0 to (2 to 32)-1 (max value represented by 32 bits)

    you can do that next time too

  3. #3
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    But make sure your UNDO tablespace is big enough to support the UNDO_RETENTION otherwise the ondo space will be reused that was supposed to be retained.
    Sanjay G.
    Oracle Certified Professional 8i, 9i.

    "The degree of normality in a database is inversely proportional to that of its DBA"

  4. #4
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    Pando cheers for that. The answer wasn't clear in the documentation I read.

    Am I right in calculating that the max value is something like 136 years. Thats a quite impressive figure.

    Sanjay,
    Is there any way to tell if the undo space is being reused by the database (ie in the alert log or something)?

    I know there are calculations to calulate the average amount of redo being used, but I can see that this could easily change as the size and usage of the database changed.
    OCP 8i DBA

  5. #5
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    136 Years ( if u speak in GB it will be 4GB ) -- This sounds quite immpressive figures.
    Last edited by abhaysk; 06-24-2003 at 07:02 AM.
    funky...

    "I Dont Want To Follow A Path, I would Rather Go Where There Is No Path And Leave A Trail."

    "Ego is the worst thing many have, try to overcome it & you will be the best, if not good, person on this earth"

  6. #6
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    Originally posted by blakmk

    Is there any way to tell if the undo space is being reused by the database (ie in the alert log or something)?
    If Oracle needs the undo space, it will overwrite the segments without careing about your UNDO_RETENTION. You will get the abit missleading this time ORA-01555 in the alert.log.
    Oracle Certified Master
    Oracle Certified Professional 6i,8i,9i,10g,11g
    email: ocp_9i@yahoo.com

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