Before postgresql 8.1.5, I could do the following to find the first lead that created a prospect in my application. SELECT Lead.LeadID, Prospect.ProspectID FROM Prospect INNER JOIN Lead USING (ProspectID) WHERE Lead.CreationDate = (SELECT MIN(Lead.CreationDate) FROM Lead AS LL WHERE LL.ProspectID = Lead.ProspectID) With 8.1.5 this now generates: ERROR: aggregates not allowed in WHERE clause SQL state: 42803 Shouldn't aggregate functions still work within correlated subQueries? I saw in the 8.1.5 release notes that this was disabled due to crashes this caused in 8.1.X versions for Postgresql. I have never experienced this with queries similar to the above.
