I answered a question on SSC with the comment that while an INT would perform better than a DATETIME in an ORDER BY query, assuming each has a viable index, that the difference wouldn't be all that terribly substantial. Then I realized, maybe that's not true. So I ran up a quick test, just to see. First I created a little test table with the right indexes and loaded it with data: CREATE TABLE dbo.IntDate (IntCol INT NOT NULL, DateCol DATETIME NOT NULL); CREATE INDEX ixInt ON dbo.IntDate(IntCol); CREATE INDEX ixDate ON dbo.IntDate(DateCol); SELECT TOP 10000 IDENTITY( INT,1,1 ) AS n INTO #Tally FROM Master.dbo.SysColumns sc1, Master.dbo.SysColumns sc2; INSERT INTO dbo.IntDate ( IntCol ,DateCol) SELECT t.n, DATEADD(dd,- t.n,GETDATE() ) FROM #Tally AS t; DROP TABLE #Tally; Then I ran these…