Re: pgsql: Make WAL segment size configurable at initdb time.

From: David Steele <david(at)pgmasters(dot)net>
To: Andres Freund <andres(at)anarazel(dot)de>
Cc: pgsql-committers(at)postgresql(dot)org
Subject: Re: pgsql: Make WAL segment size configurable at initdb time.
Date: 2018-11-10 03:50:44
Message-ID: d3c15820-562c-dcc4-5d4f-74550547e029@pgmasters.net
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On 11/9/18 10:30 PM, Andres Freund wrote:
> On 2018-11-09 21:45:18 -0500, David Steele wrote:
>> On 10/5/18 1:03 PM, David Steele wrote:
>>>
>>> So, while the WAL segment size used to be expressed in terms of 8K pages
>>> it is now expressed in terms of absolute bytes.  This seemed to me to be
>>> a very deliberate change in the original commit so I guessed it was done
>>> for clarity, but that the docs didn't get the message.
>>
>> Thoughts on this?
>>
>> I know it's minor in the grand scheme of things but it caused me some
>> confusion when I was updating pgBackRest for v11 and I imagine it might
>> do the same for others.
>
> Sorry for forgetting this, pushed.

No worries. Thanks for pushing it.

> I kinda wonder whether we should move a few GUCs out of the
> <sect1 id="runtime-config-preset">
> section. Or adapt its description. Because a significant portion of its
> contents don't accurately seem to be described by
> The following <quote>parameters</quote> are read-only, and are determined
> when <productname>PostgreSQL</productname> is compiled or when it is
> installed.
> right?

I agree that "installed" is a bit vague.

Most of them are set at compile-time, some are set at initdb, and a few
are set at CREATE DATABASE.

I'm not sure about moving any out since it seems like "presets" fits the
bill. Maybe just break it up into three sections?

--
-David
david(at)pgmasters(dot)net

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