Query Plan...

  • Hi Everybody,
    In some query plans we see some iterators have a non-zero cost even when the query cost relative to that batch is zero. Any reasons why it has to be so?

    Thanks...Arshad

  • Arsh - Monday, August 14, 2017 3:05 AM

    Hi Everybody,
    In some query plans we see some iterators have a non-zero cost even when the query cost relative to that batch is zero. Any reasons why it has to be so?

    Thanks...Arshad

    Yes.  It all estimates and no query plan "relative to batch" can actually have a zero value... just something less than 1.

    --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)

  • Jeff Moden - Monday, August 14, 2017 7:19 AM

    Arsh - Monday, August 14, 2017 3:05 AM

    Hi Everybody,
    In some query plans we see some iterators have a non-zero cost even when the query cost relative to that batch is zero. Any reasons why it has to be so?

    Thanks...Arshad

    Yes.  It all estimates and no query plan "relative to batch" can actually have a zero value... just something less than 1.

    Thanks Jeff.

Viewing 3 posts - 1 through 2 (of 2 total)

You must be logged in to reply to this topic. Login to reply