"Willis, Ian (Ento, Canberra)" <Ian.Willis@ento.csiro.au> writes:
> By external large objects I mean storing the objects as ordinary files
> through the database interface, giving you a filesystem that supports
> tranactions though a postgresql interface.
Huh? LOs stored as ordinary files would by definition *NOT* have
transactional semantics --- aborted changes wouldn't roll back, and
there'd be no way to prevent people from seeing intermediate states
of a transaction, either.
regards, tom lane