Robert Haas <robertmhaas@gmail.com> writes:
> On Sun, Jan 5, 2014 at 10:50 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Now, if bdr is installed but the validation doesn't happen unless bdr
>> is "loaded" in some sense, then that is an implementation deficiency
>> that I think we can insist be rectified before this feature is accepted.
> We could add a catalog pg_custom_reloption with a reloption namespace,
> a reloption name, and a pg_proc OID for a checker-function. This is a
> lot more overhead than just having a hook the way we do for GUCs, and
> I'm not sure how you'd handle invalidation, but in theory it solves
> the problem.
If we're willing to tie the reloption names to extension names, which
seems reasonable to me, then we don't need a new catalog --- just add
a checker-function column to pg_extension.
I don't follow your point about invalidation. Once an extension has
accepted a reloption value, it doesn't get to change its mind later;
it has to deal with that value somehow forevermore. Using a hook,
or failing to validate the value at all, certainly isn't going to make
that requirement go away.
regards, tom lane