Home Forums Article Discussions Article Discussions by Author Discuss Content Posted by Jeff Moden Find Customers Who Bought "A" and "B" But Not "C" (SQL Spackle) RE: Find Customers Who Bought "A" and "B" But Not "C" (SQL Spackle)

  • March 31, 2012 at 1:37 pm

    #1467334

    Dean Cochrane (3/30/2012)

    Berl (3/30/2012)

    Although CPU time difference is not very great, the difference is much bigger for the elapsed time.

    Elapsed time includes wait time and is not a good measure of performance.

    Actually, it is. The wait time you speak of also includes I/O time and that can be a major part of a performance problem. I do agree, though, that you really need to take "time to display" out of the picture because it will severly mask problems. It takes a certain amount of time to display a million rows and can make differences between two methods seem much more trivial than they might be.

    --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)