Date: Tue, 9 Feb 2021 12:46:36 -0500
From: Stephen Frost <sfrost@snowman.net>
To: Victor Sudakov <vas@sibptus.ru>
Cc: pgsql-admin@lists.postgresql.org
Subject: Re: wal-g (https://github.com/wal-g/wal-g) reliability
Message-ID: <20210209174636.GY27507@tamriel.snowman.net>
References: <YB0VuB8RJAKvTI6+@admin.sibptus.ru>
 <CANNMO++t7hLG2Uk-M61ohXGNhBYszSPL8vn=zP09tcRv15QB4A@mail.gmail.com>
 <YCDKyYzrv4HQZz9t@admin.sibptus.ru>
 <20210208212840.GW27507@tamriel.snowman.net>
 <YCH3pqahVncfF2O2@admin.sibptus.ru>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha512;
	protocol="application/pgp-signature"; boundary="alFF/InZuqqBdAZ2"
Content-Disposition: inline
In-Reply-To: <YCH3pqahVncfF2O2@admin.sibptus.ru>
User-Agent: Mutt/1.5.24 (2015-08-30)
Precedence: bulk


--alFF/InZuqqBdAZ2
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

Greetings,

* Victor Sudakov (vas@sibptus.ru) wrote:
> Stephen Frost wrote:
> > > 2. Is there a `wal-g backup-fetch` option for truly self-sufficient
> > > restoration?
> >=20
> > Interesting that you ask this!  I say that because it's actually a case
> > that pgbackrest contemplated and explicitly added support for-
> > specifically, if you set --archive-copy (or archive-copy=3Dtrue) and
> > disable compression (or decompress everything before you start PG), then
> > you can just start PG from the backup and it'll perform the necessary
> > recovery from the WAL and start up.  We considered this an interesting
> > use-case and used it extensively and have maintained support for it.
>=20
> Well, the release I've downloaded from https://github.com/wal-g/wal-g/rel=
eases
> does not seem to have the --archive-copy option.

Right- as I mentioned above, that's an option which pgbackrest has.

> > All that said, of course, this limits the ability to do typical PITR,
>=20
> Why? If you configure recovery_target_time and restore_command, it's all
> the same, isn't it? No matter if you have WAL archives in pg_wal, but
> it's better to have them.

If you have a restore_command configured to be able to pull from a full
repo that has all the new WAL, sure, but the idea behind archive-copy is
specifically that you can pull out that backup and restore it *without*
having to have access to the original repo.  If the assumption is that
you've got access to the full repo, then archive-copy isn't really
gaining you anything and it wouldn't make sense to use it.

Thanks,

Stephen

--alFF/InZuqqBdAZ2
Content-Type: application/pgp-signature; name="signature.asc"

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
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=vphY
-----END PGP SIGNATURE-----

--alFF/InZuqqBdAZ2--