• suhasini.m (4/8/2009)


    When i am creating a new table how to identify whether i should create a Clustered or Nonclustered Index on this table? In terms of performance which one is better?

    It's not a case of which is best. Both are usually needed. There can be only one clustered index on a table and it is recommended practive to have a clustered index on every table.

    As for nonclustered indexes, create as necessary to support the queries that run against the table.

    For some insight into choosing indexes, take a look at these:

    http://sqlinthewild.co.za/index.php/2009/01/19/index-columns-selectivity-and-equality-predicates/

    http://www.simple-talk.com/sql/performance/finding-the-causes-of-poor-performance-in-sql-server,-part-2/

    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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