David Fetter <david@fetter.org> writes:
> How big a project would it be to have generalized DDL triggers? Apart
> from resource allocation, what are some downsides of providing such a
> facility?
BEFORE triggers on the system catalogs are Right Out. In principle we
could support AFTER triggers, which would only fire after the catalog
operation is fully complete (but before it's committed of course). So
you could have a veto, but not really affect the system behavior
on-the-fly. See past discussions in the pghackers archives.
regards, tom lane