• DTA will usually recommend multi-column stats. SQL will automatically create single column stats only.

    That said, test out all of its recommendations (including the indexes) before making the changes in production. If there are any that don't give a perf improvement, don't create them.

    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

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