Re: [RFC] Extend namespace of valid guc names

On Thu, Sep 19, 2013 at 6:19 PM, Andres Freund <andres(at)2ndquadrant(dot)com> wrote:
> On 2013-09-19 14:57:53 -0400, Robert Haas wrote:
>> On Tue, Sep 17, 2013 at 6:56 PM, Andres Freund <andres(at)2ndquadrant(dot)com> wrote:
>> > I think that ship has long since sailed. postgresql.conf has allowed
>> > foo.bar style GUCs via custom_variable_classes for a long time, and
>> > these days we don't even require that but allow them generally. Also,
>> > SET, postgres -c, and SELECT set_config() already don't have the
>> > restriction to one dot in the variable name.
>>
>> Well, we should make it consistent, but I'm not sure that settles the
>> question of which direction to go.
>
> I suggested making it consistent in either form elsewhere in this
> thread, Tom wasn't convinced. I think because of backward compatibility
> concerns we hardly can restrict the valid namespace in all forms to the
> most restrictive form (i.e. guc-file.l). Quite some people use GUCs as
> variables.
> Maybe we can forbid the more absurd variants (SET "..."."..." = 3;
> SELECT set_config('...', '1', true)), but restricting it entirely seems
> to cause pain for no reason.

Yeah, I don't think I understand Tom's reasoning. I mean, why
shouldn't there be ONE rule for what can be a GUC?

--
Robert Haas
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