Re: Another documentation issue - Mailing list pgsql-general

On Wed, 2025-04-23 at 00:21 -0500, Igor Korot wrote:
> On the page https://www.postgresql.org/docs/current/runtime-config-query.html#GUC-SEQ-PAGE-COST
>
> it is only given the default value of this parameter.
>
> No min/max values are provided..
>
> The same can be sad about
> https://www.postgresql.org/docs/current/runtime-config-query.html#GUC-RANDOM-PAGE-COST

Sad.  But you can interpret it as "there is no maximum".  The actual maximum is DBL_MAX,
the biggest double precision value that your system can handle, and may depend on your
architecture.

> However, this page
> https://www.postgresql.org/docs/current/runtime-config-resource.html#GUC-EFFECTIVE-IO-CONCURRENCY
> describes both default and mn/max, however t s says:
>
> [quote]
> The default is 1 on supported systems, otherwise 0
> [/quote]]
>
> No explanation of what is "supported system" is given...
>
> And the same can be said about
> https://www.postgresql.org/docs/current/runtime-config-resource.html#GUC-MAINTENANCE-IO-CONCURRENCY.

According to the source, it is "systems that have posix_fadvise()".  We could document that,
but I don't know if it would help many people.  I am not sure how easy and feasible it is
to research which versions of which operating systems qualify.

Yours,
Laurenz Albe