Doc: shared_memory_size_in_huge_pages with the "SHOW" command.

On Fri, Oct 11, 2024 at 05:25:04PM +0900, Seino Yuki wrote:

Alternatively, the "SHOW" command can be used, though the documentation
states,
"Note that the server must be shut down to view this runtime-computed
parameter.[1]"
This wording could be misunderstood to imply that the parameter cannot be
accessed
while the server is running.

I am not sure that neither mentioning nor recommending SHOW for this
area is a good idea, the point being to encourage its use before the
server is running as we don't want to allocate anything when tuning
it.

Point taken that the current wording can be confusing because of the
"*must* be shut down". How about doing a simpler s/must/should/ for a
softer wording?
--
Michael

On Wed, Oct 16, 2024 at 09:31:49AM +0900, Michael Paquier wrote:

I am not sure that neither mentioning nor recommending SHOW for this
area is a good idea, the point being to encourage its use before the
server is running as we don't want to allocate anything when tuning
it.

Agreed.

Point taken that the current wording can be confusing because of the
"*must* be shut down". How about doing a simpler s/must/should/ for a
softer wording?

Well, the point is that you can't use "postgres -C" to view this GUC while
the server is running. I can see how the present wording might be
misinterpreted, though. Perhaps we should change this sentence to
something like:

Note that the server must be shut down to view this runtime-computed
parameter with the postgres command.

--
nathan

On Friday, October 11, 2024, Seino Yuki <seinoyu@oss.nttdata.com> wrote:

The current documentation explains the use of the postgres -C command,
but this method may be limited in DBaaS or managed service environments.
In particular, CloudNativePG does not allow the server to be stopped,
making the execution of $ postgres -C impossible.

If your environment doesn’t allow shutting down the Postgres service it
seems highly unlikely you’d be able to perform the other low-level
operating system actions required here as well.

I think the wording is fine as-is, though for consistency with an earlier
mention on the page we could instead write:

This parameter can be viewed before starting the server with a postgres command
like:

David J.

On Tue, Oct 15, 2024 at 08:26:06PM -0500, Nathan Bossart wrote:

Well, the point is that you can't use "postgres -C" to view this GUC while
the server is running. I can see how the present wording might be
misinterpreted, though. Perhaps we should change this sentence to
something like:

Note that the server must be shut down to view this runtime-computed
parameter with the postgres command.

I'm OK with the "postgres command" addition.
--
Michael

On 2024/10/16 14:18, Michael Paquier wrote:

On Tue, Oct 15, 2024 at 08:26:06PM -0500, Nathan Bossart wrote:

Well, the point is that you can't use "postgres -C" to view this GUC while
the server is running. I can see how the present wording might be
misinterpreted, though. Perhaps we should change this sentence to
something like:

Note that the server must be shut down to view this runtime-computed
parameter with the postgres command.

I'm OK with the "postgres command" addition.

Another idea is to use the same wording as for num_os_semaphores in runtime.sgml, like this:

This parameter can be viewed
before starting the server with a <command>postgres</command> command like:

Regards,

--
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION

On Wed, Oct 16, 2024 at 03:31:05PM +0900, Fujii Masao wrote:

Another idea is to use the same wording as for num_os_semaphores in runtime.sgml, like this:

This parameter can be viewed
before starting the server with a <command>postgres</command> command like:

WFM

--
nathan

Thank you, everyone.

the point being to encourage its use before the server is running
as we don't want to allocate anything when tuning it.

I was mistaken and now understand that it needs to be run before the
server is running.

Another idea is to use the same wording as for num_os_semaphores in
runtime.sgml, like this:

WFM

I've fixed the patch and will register it in the CF.

Regards,
--
Yuki Seino
NTT DATA CORPORATION

On Thu, Oct 17, 2024 at 02:07:32PM +0900, Seino Yuki wrote:

I've fixed the patch and will register it in the CF.

Thanks. Here is what I have staged for commit.

--
nathan

On Thu, Oct 17, 2024 at 04:59:54PM -0500, Nathan Bossart wrote:

Thanks. Here is what I have staged for commit.

Fine by me. Thanks.
--
Michael

On 2024/10/18 7:10, Michael Paquier wrote:

On Thu, Oct 17, 2024 at 04:59:54PM -0500, Nathan Bossart wrote:

Thanks. Here is what I have staged for commit.

Fine by me. Thanks.

LGTM, too. Thanks!

Regards,

--
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION

On Fri, Oct 18, 2024 at 02:47:37PM +0900, Fujii Masao wrote:

On 2024/10/18 7:10, Michael Paquier wrote:

Fine by me. Thanks.

LGTM, too. Thanks!

Committed.

--
nathan