I'm guessing that this isn't possible, but you guys are pretty smart. :) Short version, is there a way to implement an exclusive OR in a where clause? table1 dt1(timestamp) --------- 3 mins 5 mins 7 mins table2 dt2(timestamp), timedifference(interval) --------------- ---------------------- 4 mins 1 min ( always positive ) I want to join these two tables, grabbing the row from table 1 that has a time equal to table2's record + interval, but table 2 could have values that fall smack dab in the middle of two table1 records, and I don't want both. select t1.dt1 from table1 t1, table2 t2 where t2.dt2 + t2.timedifference = t1.dt1 XOR ;-) t2.dt2 - t2.timedifference = t1.dt1 It's not important which of the two closest times I get, but would like to get just one without being messy. Thanks for any ideas. Maybe there's a great function out there that solves this? Dave -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general