----- Original Message -----
> From: Sawada Masahiko <sawada.mshk@gmail.com>
> To: Tom Lane <tgl@sss.pgh.pa.us>
> Cc: PostgreSQL-development <pgsql-hackers@postgresql.org>
> Sent: Wednesday, 14 January 2015, 16:09
> Subject: Re: [HACKERS] Merging postgresql.conf and postgresql.auto.conf
>
> On Thu, Jan 15, 2015 at 12:37 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Sawada Masahiko <sawada.mshk@gmail.com> writes:
>>> The postgresql.auto.conf is loaded after loading of postgresql.conf
>>> whenever configuration file is loaded or reloaded.
>>> This means that parameter in postgresql.auto.conf is quite high
>>> priority, so the parameter in postgresql.conf does not work at all
>>> even if user set it manually.
>>
>>> If user want to change stopped postgresql server then user need to
>>> merge two configuration file(postgresql.conf and postgresql.auto.conf)
>>> while maintaining the consistency manually.
>>
>>>> From an operational perspective having a written config with
> duplicate
>>> entries is not good thing.
>>> I think we need to merge two configuration file into one (or more than
>>> one, if it uses like 'include' word)
>>
>>> The one solution is to add merging tool/commnand which merges two
>>> configuration file while maintaining the consistency.
>>> This topic have been already discussed?
>>
>> Yes. The entire reason that postgresql.auto.conf is separate is that
>> we despaired of reading and rewriting postgresql.conf automatically
>> without making a hash of material in the comments. Calling the logic
>> a "merge tool" does not make that problem go away.
>>
>
> The merge tool do not only to merge the all parameters in two
> configuration into one file but also to remove duplicate parameters.
> That is, the configuration files will be one file in logically.
I think the point is that you can't really interpret the context of comments with an automated tool, so you'd probably
constructa misleading conf file. I created something to mash conf files together in perl, but mash them together is
allit does: https://github.com/glynastill/pg_upgrade_conf