Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org> writes:
> All in all, Tatsuo is right in that there's no way to know what tuples
> are locked without scanning the whole table.
Sure. I was just questioning how much one needs to know that. It seems
to me that the only time you really care is when you are investigating
a hangup, and then you can get useful info from pg_locks.
regards, tom lane