Adrian Klaver <adrian(dot)klaver(at)gmail(dot)com> writes:
> Well the question is how long have those idle transactions been around?
Idle transactions shouldn't have anything to do with pg_xlog bloat.
What causes xlog bloat is inability to release old WAL because either
(a) we're not able to complete checkpoints, or (b) WAL archiving is
enabled but malfunctioning, and the old WAL segments are being kept
pending successful archiving.
Either (a) or (b) should result in bleating in the postmaster log.
regards, tom lane