From: Tom Lane <tgl@sss.pgh.pa.us>
To: Mark Dilger <mark.dilger@enterprisedb.com>
cc: Robert Haas <robertmhaas@gmail.com>, Andrew Dunstan <andrew@dunslane.net>,
        Peter Eisentraut <peter.eisentraut@enterprisedb.com>,
        Andres Freund <andres@anarazel.de>, Bruce Momjian <bruce@momjian.us>,
        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: <75CEAC23-E6A1-4976-8CFF-AD7B24647A7C@enterprisedb.com>
References: 
 <CA+TgmoboH6=SgWHPddv_8ie91Qf2ECKSvg-72aYajKb2gyLYQg@mail.gmail.com>
 <202110222351.3f42l5fgo3lw@alvherre.pgsql>
 <CA+TgmobB8cj30z6dzEf5xNTxzGRNGmkJsCr3nv_Hneo0o5kozg@mail.gmail.com>
 <3783090.1635111977@sss.pgh.pa.us>
 <CA+TgmobQxeGVtgxQz_OxdgCO4r=Tb2SaCh9FJ8Dxjaq9DxHH_g@mail.gmail.com>
 <3883429.1635171820@sss.pgh.pa.us>
 <20211025170657.ekufa7urdcyzpgdm@alap3.anarazel.de>
 <c51ede27-3b6d-1d27-9d1a-227526858db2@dunslane.net>
 <22018.1635202338@sss.pgh.pa.us>
 <d0316012-ece7-7b7e-2d36-9c38cb77cb3b@enterprisedb.com>
 <20211202221607.xovsdnoh5tpbnhbs@alap3.anarazel.de>
 <196b40be-c571-e77f-3335-920f8a00047f@enterprisedb.com>
 <2316211.1638556231@sss.pgh.pa.us>
 <CA+Tgmob0V3dJ57vKL1iouk1oLMFn-60eAUQ+ab6=1BDG7ZC8iw@mail.gmail.com>
 <2978297.1638751274@sss.pgh.pa.us>
 <CA+TgmobDY0ShV2Nso4x3mgLSA1dPvfi3KB9CK=Jo-USjWLskGA@mail.gmail.com>
 <3361296.1638825548@sss.pgh.pa.us>
 <CA+TgmoYeJt5FU5eHQ4FNxJEuDO2NJjz81quU2fSt=zQhwFU8vw@mail.gmail.com>
 <75CEAC23-E6A1-4976-8CFF-AD7B24647A7C@enterp!
 risedb.com>
Comments: In-reply-to Mark Dilger <mark.dilger@enterprisedb.com>
	message dated "Tue, 07 Dec 2021 10:26:13 -0800"
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-ID: <3506993.1638903154.1@sss.pgh.pa.us>
Content-Transfer-Encoding: quoted-printable
Date: Tue, 07 Dec 2021 13:52:34 -0500
Message-ID: <3506994.1638903154@sss.pgh.pa.us>
Archived-At: 
 <https://www.postgresql.org/message-id/3506994.1638903154%40sss.pgh.pa.us>
Precedence: bulk

Mark Dilger <mark.dilger@enterprisedb.com> writes:
> Wouldn't you be able to see what changed by comparing the last released =
tag for version X.Y against the RELX_Y_STABLE branch?  Something like `git=
 diff REL8_4_22 origin/REL8_4_STABLE > buildability.patch`?

> Having such a patch should make reproducing old corruption bugs easier, =
as you could apply the buildability.patch to the last branch that containe=
d the bug.  If anybody did that work, would we want it committed somewhere=
?  REL8_4_19_BUILDABLE or such?  For patches that apply trivially, that mi=
ght not be worth keeping, but if the merge is difficult, maybe sharing wit=
h the community would make sense.

I'm not entirely following ... are you suggesting that each released minor
version needs to be kept buildable separately?  That seems like a huge
amount of extra committer effort with not much added value.  If someone
comes to me and wants to investigate a bug in a branch that's already
out-of-support, and they then say they're not running the last minor
release, I'm going to tell them to come back after updating.

It is (I suspect) true that diffing the last release against branch
tip would often yield a patch that could be used to make an older
minor release buildable again.  But when that patch doesn't work
trivially, I for one am not interested in making it work.  And
especially not interested in doing so "on spec", with no certainty
that anyone would ever need it.

			regards, tom lane