How to check if an integer is a power of 3?

Question

I saw this question, and pop up this idea.

Answer 1

Set based solution...

DECLARE @LastExponent smallint, @SearchCase decimal(38,0)

SELECT
    @LastExponent = 79, -- 38 for bigint
    @SearchCase = 729

;WITH CTE AS
(
    SELECT
        POWER(CAST(3 AS decimal(38,0)), ROW_NUMBER() OVER (ORDER BY c1.object_id)) AS Result,
        ROW_NUMBER() OVER (ORDER BY c1.object_id) AS Exponent
    FROM
        sys.columns c1, sys.columns c2
)
SELECT
    Result, Exponent
FROM
    CTE
WHERE
    Exponent <= @LastExponent
    AND
    Result = @SearchCase

With SET STATISTICS TIME ON it record the lowest possible, 1 millisecond.