Question on table fragmentation
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  1. #1
    Join Date
    Jul 2002
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    205

    Question on table fragmentation

    Hi All,

    Is there any way to find the follwoing two points.

    1. How to know a table is how much fragmented.?
    2. How to know, how much space we can claim from the table which is fragmented?

  2. #2
    Join Date
    Mar 2006
    Location
    Charlotte, NC
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    are you using 9i or 10g above? also are you using DMTS or LMTS?

    Thanks,
    Vijay Tummala

    Try hard to get what you like OR you will be forced to like what you get.

  3. #3
    Join Date
    Jul 2002
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    It is Oracle 10g and DMTS.

  4. #4
    Join Date
    May 2002
    Posts
    2,645
    You should be using locally managed tablespaces in 10g. There is no justification whatsoever for using DMT. With LMT, fragmentation went the way of dinosaurs.

  5. #5
    Join Date
    Mar 2007
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    Ft. Lauderdale, FL
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    Quote Originally Posted by skdas View Post
    Is there any way to find the follwoing two points.

    1. How to know a table is how much fragmented.?
    2. How to know, how much space we can claim from the table which is fragmented?
    1- Yes.
    2- Provided you have up-to-date performance statistics dba_tables tells you: a) how many rows you have in your table, b) average row lenght and, c) how much overhead you have set for the table; these pieces of information allow you to tell what's your "ideal" space utilization. On the other hand dba_extents allows you to check how much space is the table actually allocating. Difference between actual nad ideal space utilization is the space you are wasting e.g. space allocated but not used to store actual data.
    Pablo (Paul) Berzukov

    Author of Understanding Database Administration available at amazon and other bookstores.

    Disclaimer: Advice is provided to the best of my knowledge but no implicit or explicit warranties are provided. Since the advisor explicitly encourages testing any and all suggestions on a test non-production environment advisor should not held liable or responsible for any actions taken based on the given advice.

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