Re: problems with "Shared Memory and Semaphores" section of docs - Mailing list pgsql-hackers

Hi,

On 2024-05-17 18:30:08 +0000, Imseih (AWS), Sami wrote:
> > The advantage of the GUC is that its value could be seen before trying to
> > actually start the server.
>
> Only if they have a sample in postgresql.conf file, right?
> A GUC like shared_memory_size_in_huge_pages will not be.

You can query gucs with -C. E.g.

postgres -D pgdev-dev -c shared_buffers=16MB -C shared_memory_size_in_huge_pages
13
postgres -D pgdev-dev -c shared_buffers=16MB -c huge_page_size=1GB -C shared_memory_size_in_huge_pages
1

Which is very useful to be able to actually configure that number of huge
pages. I don't think a system view or such would not help here.

Greetings,

Andres Freund