Home Forums Article Discussions Article Discussions by Author Discuss Content Posted by Steve Jones Indexing Computed Columns RE: Indexing Computed Columns

  • November 10, 2018 at 8:00 am

    #2013066

    I believe you meant "not" rather than "now".

    However, your first example is also non-deterministic.  Here's the proof.

    Create table dbo.SalesOrderHeader (RN INT IDENTITY(1,1),SomeDate DATETIME);
    GO
    ALTER TABLE dbo.SalesOrderHeader ADD WhichDay AS datepart(day,'20180131') PERSISTED;

    Msg 4936, Level 16, State 1, Line 1
    Computed column 'WhichDay' in table 'SalesOrderHeader' cannot be persisted because the column is non-deterministic.

    --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)