[Tom Lane - Tue at 12:23:40PM -0400]
> Look in pg_locks to see the lowest-numbered transaction ID --- each
> transaction will be holding exclusive lock on its own XID. You can
> correlate that back to pg_stat_activity via the PID.
Thanks a lot for the quick reply - I've already identified one
long-running transaction.
(I'm not allowed to order by xid, and not allowed to cast it to
anything, how come?)