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  1. #1
    Join Date
    Sep 2003
    Location
    USA
    Posts
    10

    Post Indexes

    What are Bitmapped Indexes, and what are the advantage and disadvantages of it? And can I disable Index? If so how can I do that?
    Milinda

  2. #2
    Join Date
    May 2001
    Location
    Maryland, USA
    Posts
    409
    When you have a column in which number of distinct values is small compared to number of rows in table, and if this column is used in predicate, bitmap index should be created.

    Unlike regular b-tree indexes which stores rowid for each row, Bitmap index just stores a bitmap for each key value. Bitmap indexes should not be used in OLTP tables which are involved in lot many concurrent transactions as they would cause permornance problems.
    -- Dilip

  3. #3
    Join Date
    Sep 2003
    Location
    USA
    Posts
    10
    can i disable index
    Milinda

  4. #4
    Join Date
    Nov 2002
    Location
    New Delhi, INDIA
    Posts
    1,796
    Yes,

    And what ever question you are putting up are all basic questions, which one should know if working on ORACLE. You better read the concepts guide first at http://tahiti.oracle.com and all your doubts will become clear.
    Amar
    "There is a difference between knowing the path and walking the path."

    Amar's Blog  Get Firefox!

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