> What does the MERGE command do? I have never heard of it, so I doubt
> someone is working on it.
It is basically the SQL standard version of MySQL's REPLACE syntax. It
does an update-else-insert set. However, the trick is that it uses some
sort of next key locking to ensure that it cannot fail. Something that
is impossible to do in PostgreSQL at the moment. Nested transactions
will help, however.
Chris