You can remove date is not null part from where.

Another way (SQL Server 2005 and up) would be

select * from (select myTable.*, row_number() over (partition by PartNo order by DatStMpi DESC) as rn 
from myTable where myCondition) myMaxDates where rn=1

see http://forums.asp.net/t/1380333.aspx

>Is there any other way to get the record with the greatest datstmpi value without having to use the middle select statment? I believe this may be what is slowing the process, having to pull 75000 plus records on every loop iteration.
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>( SELECT webprddt6.drawmfai.partno, MAX(webprddt6.drawmfai.datstmpi) AS MaxDate 
FROM webprddt6.drawmfai Where toolinspr = 0 And conformir = 0 And DATE(datstmpin) is Not NULL 
GROUP BY webprddt6.drawmfai.partno)
>

>