Denormailzed columns
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Thread: Denormailzed columns

  1. #1
    Join Date
    May 2006
    Posts
    41

    Denormailzed columns

    Hi,

    what is meant by denormalized columns?
    When it's required/when we'll create it & how the values for these columns are obtained?

    Can anyone explain this concept with an example?

    Thanks
    Last edited by davey23uk; 12-12-2006 at 12:50 PM.

  2. #2
    Join Date
    Nov 2000
    Location
    Pittsburgh, PA
    Posts
    4,021
    I'm guessing you mean to say denormalized table. An example would be for phone number. Any person can have a home, cell, work, and fax numbers. Given that the is a one to many relationship between person and phone number, you could store phone number as a separate table from person with a primary key consisting of person id, and phone number type. But doing so will require a join to bring back person and phone number, so instead you can denormalize the table by making 4 extra columns in your person table. One for each type of number that you track.
    this space intentionally left blank

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