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In n Exist

  • July 8, 2008 at 2:06 pm

    #193532

    what is the main difference between In and Exist?

  • July 8, 2008 at 2:44 pm

    #839776

    IN has the same execution plan as an INNER JOIN. EXISTS requires the use of a correlated subquery and is a form of RBAR that is sometimes faster than IN and sometimes slower. Typically, I'll use the Inner Join instead of using either... but sometimes... it all depends on testing. 😉

    The rest of the information you seek is in Books Online.

    --Jeff Moden

    RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
    First step towards the paradigm shift of writing Set Based code:
    ________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.

    Change is inevitable... Change for the better is not.

    Helpful Links:
    How to post code problems
    How to Post Performance Problems
    Create a Tally Function (fnTally)

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