Re: Postgres and --config-file option

On Sat, Jan 13, 2024 at 01:39:50PM +0300, Aleksander Alekseev wrote:
> OK, let's check section "20.1.4. Parameter Interaction via the Shell"
> [1] of the documentation. Currently it doesn't tell anything about the
> ability to specify GUCs --like-this, unless I missed something.

It appears to be documented for 'postgres' as follows [0]:

--name=value
Sets a named run-time parameter; a shorter form of -c.

and similarly within the --help output:

--NAME=VALUE set run-time parameter

Its documentation also describes this method of specifying parameters in
the 'Examples' section. The section you refer to calls out "-c", so it is
sort-of indirectly mentioned, but that might be a bit of a generous
assessment.

> Should we remove --config-file from the error message to avoid any
> confusion? Should we correct --help output? Should we update the
> documentation?

It might be worthwhile to update the documentation if it would've helped
prevent confusion here.

Separately, I noticed that this is implemented in postmaster.c by looking
for the '-' option character returned by getopt(), and I'm wondering why
this doesn't use getopt_long() instead. AFAICT this dates back to the
introduction of GUCs in 6a68f426 (May 2000).

[0] https://www.postgresql.org/docs/devel/app-postgres.html

--
Nathan Bossart
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