You can try a quirky update (QU).
DECLARE @MachineID INT = 0
,@Pressure FLOAT = 0
UPDATE u WITH(TABLOCKX)
SET Pressure = CASE WHEN Pressure = 0
THEN @Pressure ELSE Pressure END
,@Pressure = CASE WHEN Pressure = 0 AND @MachineID = MachineID
THEN @Pressure ELSE Pressure END
,@MachineID = MachineID
FROM dbo.UpdateGaps u
OPTION(MAXDOP 1)
Edit: Ooops! Initially forgot to account for change in Machine ID.
My thought question: Have you ever been told that your query runs too fast?
My advice:
INDEXing a poor-performing query is like putting sugar on cat food. Yeah, it probably tastes better but are you sure you want to eat it?
The path of least resistance can be a slippery slope. Take care that fixing your fixes of fixes doesn't snowball and end up costing you more than fixing the root cause would have in the first place.
Need to UNPIVOT? Why not CROSS APPLY VALUES instead?[/url]
Since random numbers are too important to be left to chance, let's generate some![/url]
Learn to understand recursive CTEs by example.[/url]
[url url=http://www.sqlservercentral.com/articles/St