From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andres Freund <andres@anarazel.de>
cc: Robert Haas <robertmhaas@gmail.com>, Andrew Dunstan <andrew@dunslane.net>,
        Alvaro Herrera <alvherre@alvh.no-ip.org>,
        PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: pg_dump versus ancient server versions
In-reply-to: <20211025170657.ekufa7urdcyzpgdm@alap3.anarazel.de>
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Comments: In-reply-to Andres Freund <andres@anarazel.de>
	message dated "Mon, 25 Oct 2021 10:06:57 -0700"
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Date: Mon, 25 Oct 2021 13:14:19 -0400
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Andres Freund <andres@anarazel.de> writes:
> On 2021-10-25 10:23:40 -0400, Tom Lane wrote:
>> It seems like a fresh checkout from the repo would be little more expen=
sive
>> than the current copy-a-checkout process.)

> I haven't looked in detail, but from what I've seen in the logs the
> is-there-anything-new check is already not cheap, and does a checkout / =
update
> of the git directory.

Yeah, you probably need a checkout to apply the rule about don't rebuild
after documentation-only changes.  But it seems like the case where the
branch tip hasn't moved at all could be optimized fairly easily.  I'm not
sure it's worth the trouble to add code for that given our current usage
of the buildfarm; but if we were to start tracking branches that only
change a couple of times a year, it would be.

			regards, tom lane