Home Forums Article Discussions Article Discussions by Author Discuss content posted by Gail Shaw Stairway to Transaction Log Management in SQL Server, Level 7: Dealing with Excessive Log Growth RE: Stairway to Transaction Log Management in SQL Server, Level 7: Dealing with Excessive Log Growth

  • November 27, 2012 at 6:44 pm

    #1562905

    Good stuff to read. A question on index rebuild

    Index rebuilds

    Rebuilding an index offline, using ALTER INDEX REBUILD (or the deprecated DBCC DBREINDEX in SQL Server 2000) drops the target index and rebuilds it from scratch (online index rebuilds do not drop the existing index until the end of the rebuild operation).

    I read an article by Paul on index rebuild. In his blog, he mention "Index rebuild (whether online or offline, and at least as far back as 7.0) will create a new copy of the index before dropping the old copy". This is what I thought, otherwise rolling back an offline index rebuild will take a considerable time.

    http://www.sqlskills.com/blogs/paul/post/Search-Engine-QA-19-Misconceptions-around-index-rebuilds-(allocation-BULK_LOGGED-mode-locking).aspx

    It seem this article states offline index rebuild will drop the existing index before creating a new index?

    Just wanted to clarify if offline index really do drop existing index before the new ones are created and under what circumstance will this happen. i.e. does the statement mean logical metadata are marked "deleted" but actual index still exists, etc.

    Thanks in advance for explaination.

    Simon

    Simon Liew
    Microsoft Certified Master: SQL Server 2008