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Creating Unique Index on the column with the existing duplicates

  • April 29, 2008 at 2:00 pm

    #181749

    Hi,

    Is there any way to "cheat" on SQL on creating a unique index/constraint for the column that already has duplicates?

    Let's say I do not care much that there are already some dups in the table (or even want to keep them) but at the same time I want to make sure it wont happen in the future?

    Thanks!

  • April 29, 2008 at 2:15 pm

    #808666

    A index is either unique or it's not unique. To do what you want, you'll probably need a trigger, and it will hurt your insert/update performance.

    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

    We walk in the dark places no others will enter
    We stand on the bridge and no one may pass

  • April 29, 2008 at 2:22 pm

    #808670

    A partitioned table might allow you to do that, but not a regular table.

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