[PATCH] force_parallel_mode and GUC categories

Forking this thread
https://www.postgresql.org/message-id/20210403154336.GG29125%40momjian.us

On Sat, Apr 3, 2021 at 08:38:18PM +0530, aditya desai wrote:
> > > >> Yes, force_parallel_mode is on. Should we set it off?

Bruce Momjian <bruce(at)momjian(dot)us> writes:
> > > > Yes. I bet someone set it without reading our docs:
...
> > > > We might need to clarify this sentence to be clearer it is _only_ for
> > > > testing.

On Sat, Apr 03, 2021 at 11:39:19AM -0400, Tom Lane wrote:
> > > I wonder why it is listed under planner options at all, and not under
> > > developer options.

On Sat, Apr 3, 2021 at 10:41:14AM -0500, Justin Pryzby wrote:
> > Because it's there to help DBAs catch errors in functions incorrectly marked as
> > parallel safe.

On Sat, Apr 03, 2021 at 11:43:36AM -0400, Bruce Momjian wrote:
> Uh, isn't that developer/debugging?

I understood "developer" to mean someone who's debugging postgres itself, not
(say) a function written using pl/pgsql. Like backtrace_functions,
post_auth_delay, jit_profiling_support.

But I see that some "dev" options are more user-facing (for a sufficiently
advanced user):
ignore_checksum_failure, ignore_invalid_pages, zero_damaged_pages.

Also, I understood this to mean the "category" in pg_settings, but I guess
what's important here is the absense of the GUC in the sample/template config
file. pg_settings.category and the sample headings it appears are intended to
be synchronized, but a few of them are out of sync. See attached.

+1 to move this to "developer" options and remove it from the sample config:

# - Other Planner Options -
#force_parallel_mode = off

--
Justin