Re: No discussion of custom variables; no "See also" for set_config, current_setting, pg_settings

Thanks for the quick response.

It’s a clearly useful, simplifying feature. Unless it is likely to be removed at some point, I propose it should be documented and declared supported wherever relevant.

In any event, I am happy to prepare some documentation changes that mention these caveats, but I won’t if there is no chance of it being accepted. Are we totally opposed?

> On Sep 2, 2022, at 15:16 , Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>
> PG Doc comments form <noreply(at)postgresql(dot)org> writes:
>> A reader of this section
>> https://www.postgresql.org/docs/current/sql-set.html of the documentation
>> might be forgiven for thinking that Postgres does not support custom
>> variables.
>
> They are, in fact, *not* a supported feature. The only intended use
> of non-core GUCs was for extensions' parameters. People have abused the
> mechanism to create ad-hoc session variables, but we don't encourage it.
> The underlying code won't scale to large numbers of variables, there's
> no way to declare properties of such a variable in SQL, etc.
>
> There's been an ongoing effort to create a respectable substitute,
> but it still hasn't gotten across the finish line [1].
>
> regards, tom lane
>
> [1] https://commitfest.postgresql.org/39/1608/