For both cases, you could COPY your file into a temporary table and do a
big JOIN with your existing table, one for inserting new rows, and one for
updating existing rows.
Doing a large bulk query is a lot more efficient than doing a lot of
selects. Vacuum afterwards, and you'll be fine.
---------------------------(end of broadcast)---------------------------
TIP 1: if posting/reading through Usenet, please send an appropriate
subscribe-nomail command to [EMAIL PROTECTED] so that your
message can get through to the mailing list cleanly