=?iso-8859-1?q?Erik=20Ronstr=F6m?= <kvarken(at)yahoo(dot)com> writes:
> If the table has OIDs (which is the default), you can use the OID as a
> unique identifier for a row.
You could also use CTID in the same way; this works on all tables.
It does require that no one else is trying to update the same row at
about the same time, though.
regards, tom lane