This view is designed along the same lines as pg_file_settings, to wit
it shows what is currently in the file, not what the postmaster has
loaded as the active settings. That allows it to be used to pre-vet
edits before issuing SIGHUP. As with the earlier view, go out of our
way to allow errors in the file to be reflected in the view, to assist
that use-case.
(We might at some point invent a view to show the current active settings,
but this is not that patch; and it's not trivial to do.)
Haribabu Kommi, reviewed by Ashutosh Bapat, Michael Paquier, Simon Riggs,
and myself
Discussion: https://postgr.es/m/CAJrrPGerH4jiwpcXT1-46QXUDmNp2QDrG9+-Tek_xC8APHShYw@mail.gmail.com
Quite a few of our built-in system views were not exercised anywhere
in the regression tests. This is perhaps not so exciting for the ones
that are simple projections/joins of system catalogs, but for the ones
that are wrappers for set-returning C functions, the omission translates
directly to lack of test coverage for those functions.
In many cases, the reason for the omission is that the view doesn't have
much to do with any specific SQL feature, so there's no natural place to
test it. To remedy that, invent a new script sysviews.sql that's dedicated
to testing SRF-based views. Move a couple of tests that did fit this
charter into the new script, and add simple "count(*)" based tests of
other views within the charter. That's enough to ensure we at least
exercise the main code path through the SRF, although it does little to
prove that the output is sane.
More could be done here, no doubt, and I hope someone will think about
how we can test these views more thoroughly. But this is a starting
point.
Discussion: https://postgr.es/m/19359.1485723741@sss.pgh.pa.us
