Home Forums SQL Server 2008 SQL Server 2008 - General created a index rebuild job want to understand what happens when it runs RE: created a index rebuild job want to understand what happens when it runs

  • May 12, 2014 at 5:41 am

    #1712620

    ScottPletcher (5/9/2014)

    Jeff Moden (5/7/2014)

    On the SORT IN TEMPDB thing... It'll only affect TEMPDB by 10 or 20% of what the largest index is.

    I don't understand the rationale for that statement. I don't see how the total tempdb space used can be any smaller than the largest index size.

    I agree that the documentation that MS provides states that you must have enough space available to TEMPDB to hold the leaf level of the entire index if the SORT_IN_TEMPDB option is used. I've never seen that happen, though, despite rebuilding some rather large clustered indexes. In fact, the TEMPDB space used for an index rebuild with the SORT_IN_TEMPDB option turned on can be 0. From http://technet.microsoft.com/en-us/library/ms188281.aspx...

    Note

    If a sort operation is not required or if the sort can be performed in memory, the SORT_IN_TEMPDB option is ignored.

    --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.

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