I kept looking and the combination of parameters passed to the select that seems to hang ($sth3) ends up returning NULL when I run it against the development db. Using declare @date datetime select @date = max(date) from dbo.table3 where a = '020' and b = '451' select @date I've now been waiting for over 10min to see a result returned in isql. Any other combo of a and b that I know to be in the input causes a return immediately. Running a similar select (w/o all the declare junk) against Informix, with a table with almost as many rows as its Sybase counterpart, returns the select within less than a second. I suspect I'll have to create some sort of hash containing the max dates at the beginning of the program and then query against the hash later on. Not the kind of overhead I'd want to deal with when the number of input records is relatively small. --Curt