Re: [PATCH] Store Extension Options

On Sun, Jan 5, 2014 at 10:50 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Fabrízio de Royes Mello <fabriziomello@gmail.com> writes:
>> You are correct. pg_dump export reloptions using "WITH" clause of CREATE
>> TABLE statement. I.e.:
>
>> CREATE TABLE foo (
>> )
>> WITH (autovacuum_enabled=false, bdr.do_replicate=false);
>
>> So if this statement checks for 'bdr' extension is loaded then in partial
>> restore it can be fail.
>
> I see absolutely *nothing* wrong with failing that command if bdr is not
> installed.  For an analogy, if this table includes a column of type bar
> defined by some extension baz, we are certainly going to fail the
> CREATE TABLE if baz isn't installed.
>
> 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.

-- 
Robert Haas
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