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what is the usage of the bit map index and where it use

Discussion in 'SQL PL/SQL' started by jakirajam, Feb 24, 2010.

  1. jakirajam

    jakirajam Active Member

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    what is the usage of the bit map index and where it use
     
  2. salmankhalid

    salmankhalid Forum Advisor

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    In Simple Words i can say this as

    Conventional wisdom holds that bitmap indexes are most appropriate for columns having low distinct values—such as GENDER, MARITAL_STATUS, and RELATION. This assumption is not completely accurate, however. In reality, a bitmap index is always advisable for systems in which data is not frequently updated by many concurrent systems. In fact, as I'll demonstrate here, a bitmap index on a column with 100-percent unique values (a column candidate for primary key) is as efficient as a B-tree index.

    I have found an article in this, i will post it later in Articles section.....