From: Tom Lane <tgl@sss.pgh.pa.us>
To: Thomas Munro <thomas.munro@gmail.com>
cc: Tomas Vondra <tomas@vondra.me>, Andres Freund <andres@anarazel.de>,
        Michael Paquier <michael@paquier.xyz>,
        Andrew Dunstan <andrew@dunslane.net>, Amul Sul <sulamul@gmail.com>,
        Zsolt Parragi <zsolt.parragi@percona.com>,
        Robert Haas <robertmhaas@gmail.com>, Chao Li <li.evan.chao@gmail.com>,
        Anthonin Bonnefoy <anthonin.bonnefoy@datadoghq.com>,
        Fujii Masao <masao.fujii@gmail.com>,
        Jakub Wartak <jakub.wartak@enterprisedb.com>,
        PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: pg_waldump: support decoding of WAL inside tarfile
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Comments: In-reply-to Thomas Munro <thomas.munro@gmail.com>
	message dated "Fri, 03 Apr 2026 11:41:33 +1300"
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Thomas Munro <thomas.munro@gmail.com> writes:
> On Fri, Apr 3, 2026 at 7:48 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Interestingly, pg_verifybackup's t/003_corruption.pl test also fails
>> with the same issue, so apparently this platform is even more
>> aggressive about sparse-ifying files than Thomas' FreeBSD box.

> Looks like sparse files and BTRFS might be a red herring then, if it's
> simply been told to put a pax header on every file?

It looked to me that it was only putting a pax header on sparse-ified
WAL files.

> How about using --format=ustar, instead of that sparse control stuff?

I did it that way for GNU tar, but did not research whether bsdtar
will take that option.  Feel free to hack on ebba64c08 some more.

(It seems though that the two tars' locutions for "write to stdout"
are different, so we might have to have separate tests even if they
end up pushing the same option.)

			regards, tom lane