Home Forums Database Design Design Ideas and Questions Is Having Primary key on a table essential? RE: Is Having Primary key on a table essential?

  • May 6, 2013 at 9:17 am

    #1612658

    Grant Fritchey (5/6/2013)

    Just remember that if you have a clustered index that is not unique, then SQL Server makes it unique through an internal process called a uniquifier. It's additional storage and maintenance overhead. Since you're saying this is a high volume part of your system, having that non-unique cluster might be an issue. Just something else to consider.

    +1. Good to see emphasis on this. That's also why I said (in my previous post)...

    and your clustered index will be UNIQUE which will cause great benefit...

    ... although I didn't explain why like Grant did.

    --Jeff Moden

    RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
    First step towards the paradigm shift of writing Set Based code:
    ________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.

    Change is inevitable... Change for the better is not.

    Helpful Links:
    How to post code problems
    How to Post Performance Problems
    Create a Tally Function (fnTally)