Re: Feature patch 1 for plperl [PATCH]

Andrew Dunstan <andrew(at)dunslane(dot)net> writes:
> Tom Lane wrote:
>> No, they have to all be PGC_POSTMASTER to answer that concern. Only
>> breaking things for superusers isn't really that big an improvement
>> over breaking them for everybody.

> Well, I don't know about Tim but I think I could live with that. And
> when we get some actual experience with using them we'll have a better
> handle on whether or not it gives us any pain.

Upon further review, PGC_POSTMASTER isn't going to work because of this
in guc.c:

/*
* Only allow custom PGC_POSTMASTER variables to be created during shared
* library preload; any later than that, we can't ensure that the value
* doesn't change after startup. This is a fatal elog if it happens; just
* erroring out isn't safe because we don't know what the calling loadable
* module might already have hooked into.
*/
if (context == PGC_POSTMASTER &&
!process_shared_preload_libraries_in_progress)
elog(FATAL, "cannot create PGC_POSTMASTER variables after startup");

We certainly don't want to make it such that plperl *has* to be
preloaded, so PGC_POSTMASTER is out. However, I think PGC_SIGHUP
would be enough to address my basic worry, which is that people
shouldn't be depending on the ability to set these things within
an individual session.

regards, tom lane