Does Index Rebuilding Also Update Data Distribution Statistics?

  • I have read considerably about this subject and seen many different opinions.

    If someone is an authority on this subject, I'd like to know conclusively:

    1. Does rebuilding indexes also update data distribution statistics? Or,

    2. Are the 2 operations completely unrelated and to be implemented separately without consideration for the other activity?

    LC

  • Rebuilding indexes automatically updates the stats. Reorganizing indexes does not.

    There's good data on rebuilds here http://sqlserverpedia.com/blog/sql-server-bloggers/update-statistics-before-or-after-an-index-rebuild/.

    - Gus "GSquared", RSVP, OODA, MAP, NMVP, FAQ, SAT, SQL, DNA, RNA, UOI, IOU, AM, PM, AD, BC, BCE, USA, UN, CF, ROFL, LOL, ETC
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  • Thanks, GSquared.

    The link you suggested gave me the most unambigous answer I've ever received.

    I am in your debt. 😀

    LC

  • crainlee2 (12/17/2009)


    1. Does rebuilding indexes also update data distribution statistics?

    Rebuilding an index updates the statistics associated with that index. It does not update any other statistics on that table. Column statistics (stats not associated with indexes) are not affected by index rebuilds.

    There's a powerpoint deck on my blog that has some info on that. http://sqlinthewild.co.za/index.php/resources/ Under PASS Community Summit 2009

    Gail Shaw
    Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
    SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability

    We walk in the dark places no others will enter
    We stand on the bridge and no one may pass
  • Gail,

    I reviewed your PowerPoint presentation. Unambiguous and to the point. Excellent. Thanks.

    And I think I want to attend PASS next year.

    LC

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