Are these two queries logically equivalent?

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sql-server query performance query-refactor query-performance

                          Are these two queries logically equivalent?

    DECLARE @DateTime DATETIME = GETDATE()

Query 1

    SELECT *
    FROM   MyTable
    WHERE  Datediff(DAY, LogInsertTime, @DateTime) > 7   

Query 2

    SELECT *
    FROM   MyTable
    WHERE  LogInsertTime < @DateTime - 7 

If they are not logically equivalent, can you give me the logical equivalent of the first query so that the WHERE clause can effectively use an index (i.e. eliminate function wrapping)?

Asked by Alf47 (981 rep)

Oct 17, 2012, 03:13 PM
Last activity: Nov 1, 2014, 01:25 AM

Are these two queries logically equivalent?

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