Home Forums SQL Server 2012 SQL Server 2012 - T-SQL Any benefit in a covering non-clustered index on clustered index columns? RE: Any benefit in a covering non-clustered index on clustered index columns?

  • October 8, 2015 at 5:00 am

    #1832253

    Thanks Gail. Sounds like more-trouble-than-it-is-worth 🙂

    In the main all - but I ought to make a Belt & Braces test to be sure ... - my Lookup Tables are pretty small.

    Today's panic came about because there were two unique columns (one was the clustered index) and the Lookup was on the other column which had overlooked being indexed, so I set about doing a series of tests (once I'd created the non clustered unique index with both INCLUDE and FILTER) to see whether there appeared to be any benefit for a covering index on the Clustered Index key column(s).