Re: [PATCH] Store Extension Options

On Sun, Feb 9, 2014 at 2:22 PM, Fabrízio de Royes Mello <fabriziomello@gmail.com> wrote:
>
>
> On Sat, Jan 11, 2014 at 2:47 AM, Peter Eisentraut <peter_e@gmx.net> wrote:
> >
> > On Sat, 2014-01-11 at 00:48 -0200, Fabrízio de Royes Mello 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.
> > > >
> >
> > > Check if extension is already installed is not enough for the first
> > > version of this feature?
> >
> > Elsewhere it was argued that tying this to extensions is not
> > appropriate.  I agree.
> >
> > It depends on how this feature is supposed to be used exactly.  A
> > replication plugin might very well be loaded via
> > session_preload_libraries and not appear in SQL at all.  In that case
> > you need some C-level hook.  In another case, an extension might want to
> > inspect relation options from user-space triggers.  So you'd need to
> > register some SQL-level function for option validation.
> >
> > This could end up being two separate but overlapping features.
> >
>
> Hi all,
>
>
> I taken this weekend to work on this patch and on monday or tuesday I'll send it.
>
> But I have some doubts:
>
> 1) I'm not convinced to tying this to extensions. I think this feature must enable us to just store a custom GUC. We can set custom GUCs in a backend session using "SET class.variable = value", and this feature could just enable us to store it for relations/attributes. Without the complexity and overhead to register a function to validate them. That way we can use this feature to extensions and other needs too.
>
> 2) If we're implement the Robert's idea to have a function to validate the extension options then we must think about how a extension developer will register this function. Beacuse when we install a extension must have one way to get de pg_proc OID and store it in the pg_extension (or a different catalog). Or we'll implement some way to register this function at the SQL level, like "ALTER EXTENSION bdr SET VALIDATE FUNCTION bdr_options_validate();" or another sintax of course.
>  
> I don't know if you guys understood my concerns!! :-)
>
> Comments?
>

Hi all,

The attached patch implements the first option that I suggested before.

Regards,

--
Fabrízio de Royes Mello
Consultoria/Coaching PostgreSQL
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