Re: proposal: a validator for configuration files

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Florian Pflug <fgp@phlo.org>
Cc: Alexey Klyukin <alexk@commandprompt.com>, Robert Haas <robertmhaas@gmail.com>, Selena Deckelmann <selena@chesnok.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2011-06-20T17:22:06Z
Lists: pgsql-hackers
Florian Pflug <fgp@phlo.org> writes:
> On Jun20, 2011, at 18:16 , Tom Lane wrote:
>> This is already known to happen: there are cases where the postmaster
>> and a backend can come to different conclusions about whether a setting
>> is valid (eg, because it depends on database encoding).  Whether that's
>> a bug or not isn't completely clear, but if this patch is critically
>> dependent on the situation never happening, I don't think we can accept
>> it.

> Does that mean that some backends might currently choose to ignore an
> updated config file wholesale on SIGUP (because some settings are invalid)
> while others happily apply it? Meaning that they'll afterwards disagree
> even on modified settings which *would* be valid for both backends?

Yes.  I complained about that before:
http://archives.postgresql.org/pgsql-hackers/2011-04/msg00330.php
but we didn't come to any consensus about fixing it.  This patch might
be a good vehicle for revisiting the issue, though.

			regards, tom lane