Home Forums SQL Server 2005 SQL Server 2005 Performance Tuning Problem with "If Exists (Select ...) Or Exists (Select ...)" RE: Problem with "If Exists (Select ...) Or Exists (Select ...)"

  • January 9, 2013 at 7:43 am

    #1575258

    The client's database has a nightly maintenance job to reindex.

    Really, I was just wondering if there was a well known reason why

    If A Or B

    {Something}

    might be massively slow while

    If A

    {Something}

    Else If B

    {Something}

    is lightning fast. Does SQL try to do something 'clever' with "If A Or B" that it can't do with "If A Else If B"? But if it's "just one of those (performance) things", so be it and thanks for your time!