SQL Server Performance

Using Not Exist in SQL

Discussion in 'SQL Server 2005 General Developer Questions' started by skd, Dec 5, 2007.

  1. skd New Member

    Hi,Wanted to know if I can use some join or a better way
    Thanks
    skd, Dec 5, 2007
    #2

  2. Adriaan New Member

    The NOT EXISTS subqueries are correct.
    You might get better performance with LEFT JOINs and NULL criteria, but it all depends on the actual data - so you need to compare both versions:
    SELECT DISTINCT parid FROM pardat
    LEFT JOIN dweldat ON dweldat.parid = pardat.parid
    LEFT JOIN comdat ON comdat.parid = pardat.parid
    WHERE dweldat.parid IS NULL AND comdat.parid IS NULL
    By the way - why the quotes around the identifier names? That is rather old-fashioned.
    Adriaan, Dec 5, 2007
    #3

  3. FrankKalis Moderator

    Looks like the original post has been edited and some important fragments been removed.
    FrankKalis, Dec 5, 2007
    #4

  4. Madhivanan Moderator

    Madhivanan, Dec 6, 2007
    #5

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