Thanks GSquared

I realized that as soon as I saw the specs. I "inherited" that B machine and should not have assumed.

When I saw TableScan I added indexes for type...

Thanks Gail . . .

This is the reply Iposted for another respondent. Machine hardware specs listed below.

Here's the stored proc. I ran it with these paramter values in Management...

Thanks . . .

Here's the stored proc. I ran it with these paramter values in Management Studio .@NumberOfReadings = 5, @Type = 1 and @Station = 1.

;WITH LatestMeasurement(measurement_timestamp, measurement_value)

AS

(SELECT...