Re: make MaxBackends available in _PG_init

From: Nathan Bossart <nathandbossart(at)gmail(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: Robert Haas <robertmhaas(at)gmail(dot)com>, Andres Freund <andres(at)anarazel(dot)de>, Julien Rouhaud <rjuju123(at)gmail(dot)com>, Michael Paquier <michael(at)paquier(dot)xyz>, "Bossart, Nathan" <bossartn(at)amazon(dot)com>, Fujii Masao <masao(dot)fujii(at)oss(dot)nttdata(dot)com>, "wangsh(dot)fnst(at)fujitsu(dot)com" <wangsh(dot)fnst(at)fujitsu(dot)com>, Bharath Rupireddy <bharath(dot)rupireddyforpostgres(at)gmail(dot)com>, Greg Sabino Mullane <htamfids(at)gmail(dot)com>, "pgsql-hackers(at)lists(dot)postgresql(dot)org" <pgsql-hackers(at)lists(dot)postgresql(dot)org>
Subject: Re: make MaxBackends available in _PG_init
Date: 2022-04-12 22:26:16
Message-ID: 20220412222616.GA2113503@nathanxps13
Views: Raw Message | Whole Thread | Download mbox | Resend email
Lists: pgsql-hackers

On Tue, Apr 12, 2022 at 05:46:36PM -0400, Tom Lane wrote:
> Nathan Bossart <nathandbossart(at)gmail(dot)com> writes:
>> If we allow changing GUCs in _PG_init() and provide another hook where
>> MaxBackends will be initialized, do we need to introduce another GUC flag,
>> or can we get away with just blocking all GUC changes when the new hook is
>> called? I'm slightly hesitant to add a GUC flag that will need to manually
>> maintained. Wouldn't it be easily forgotten?
> On the whole I think Robert's got the right idea: we do not really
> need an enforcement mechanism at all. People who are writing
> extensions that do this sort of thing will learn how to do it right.
> (It's not like there's not a thousand other things they have to get
> right.)

Okay. So maybe we only need the attached patches. 0001 is just 5ecd018
un-reverted, and 0002 is Julien's patch from a few weeks ago with some
minor edits.

Nathan Bossart
Amazon Web Services:

Attachment Content-Type Size
v3-0001-Fix-comments-about-bgworker-registration-before-M.patch text/x-diff 3.0 KB
v3-0002-Add-a-new-shmem_request_hook-hook.patch text/x-diff 2.9 KB

In response to


Browse pgsql-hackers by date

  From Date Subject
Next Message David G. Johnston 2022-04-12 23:24:17 Re: Improving the "Routine Vacuuming" docs
Previous Message Peter Geoghegan 2022-04-12 21:53:03 Improving the "Routine Vacuuming" docs