indexes become unuseable after certain amount of data going in
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Thread: indexes become unuseable after certain amount of data going in

  1. #1
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    indexes become unuseable after certain amount of data going in

    We have one job to rebuild indexes every weekend and I asked my colleague why and he told me b/c certain amount of data change, indexes become unusable. I am new with this app so don't know 100% what's going on but as far as Oracle concern, I think indexes only become UNUSABLE when we rebuild the tables so rowid change which made indexes unuable. I am not sure about amount of data change which made indexes unusable.

    Please give me some feedback.
    thanks,

  2. #2
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    Maybe the collegue meant unusable in an informal sense, rather than unusable in the strict Oracle sense.

    There also is a SQL*Loader option to skip index maintenance that would render the indexes actually unusable.
    David Aldridge,
    "The Oracle Sponge"

    Senior Manager, Business Intelligence Development
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    Oracle ACE

  3. #3
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    Or, as is my case, the application can use sqlloader direct and load duplicates into a table via a flatfile. Then when sqlloader goes to build the (unique) index, it is in a unusable state.
    I remember when this place was cool.

  4. #4
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    there were no SQL loader involved on this app, so I guess he means unuseable in informal sense which I completely agreed. So, you guys think rebuild indexes once a week should be ok?

  5. #5
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    Not without some reason for doing so. What does unusable really mean in the sense that it's being used here?
    David Aldridge,
    "The Oracle Sponge"

    Senior Manager, Business Intelligence Development
    XM Satellite Radio
    Washington, DC

    Oracle ACE

  6. #6
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    Quote Originally Posted by matthew00
    there were no SQL loader involved on this app, so I guess he means unuseable in informal sense which I completely agreed. So, you guys think rebuild indexes once a week should be ok?

    Well, that is a question that can open a can of worms, I'll give you the standard dba answer.....it depends.

    How much space is reclaimed after the rebuild?
    I remember when this place was cool.

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