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Does design time column ordering impact performance?

  • May 25, 2004 at 3:53 am

    #85121

    Hi,

    Does anyone know if the order in which you define columns within a table has an impact on performance in SQL2K??

    I've had a dig around and can't find any artciles which give an opinion either way.

     

    Thanks

     

    Jeet


    Thanks Jeet

  • May 25, 2004 at 6:26 am

    #507631

    I would say no. You read by pages, and a page has to contain an entire row, so the order wouldn't matter.  I suppose that the query processor could short circuit some reads if it knew the columns where the first coulple on the page, but I doubt it. There is an offset in the header, so it would just "jump" to that memory location to get the data.

    For indexes, order does matter.

  • May 25, 2004 at 10:19 am

    #507714

    I don't remember the specifics, but SQL will put the fields out how it wants them.

    I know Fixed fields are first, followed by Var..., and there is something special about nullable Var...

    So I wouldn't get concerned, it probably won't help.


    KlK

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