Message-ID: <de5e2353662f14bd127ab4dcbe15d8dad8eb566b.camel@cybertec.at>
Subject: Re: Clarify base backups and local pg_wal recycling
From: Laurenz Albe <laurenz.albe@cybertec.at>
To: Toppr Tenali <shreeharish271203@gmail.com>,
	pgsql-docs@lists.postgresql.org
Date: Wed, 30 Sep 2026 15:13:07 +0200
In-Reply-To: <91E1FA52-66B0-44F5-91C6-17FF3B5D23AB@gmail.com>
References: <91E1FA52-66B0-44F5-91C6-17FF3B5D23AB@gmail.com>
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On Tue, 2026-09-29 at 21:03 +0530, Toppr Tenali wrote:
> I would like to suggest a clarification to the PostgreSQL documentation r=
egarding base
> backups and local WAL recycling.
>=20
> The documentation explains separately that:
>=20
> - archived WAL required by a base backup can eventually be deleted once t=
hat backup
>   is safely archived

I'd say that is wrong - you need to *retain* the WAL required to recover a =
backup,
otherwise you cannot restore it.  Where in the documentation do you see tha=
t sentence?

> - WAL segments in pg_wal can be recycled or removed after they are no lon=
ger needed
>   and, when archiving is enabled, have been successfully archived.

Right, but you forgot that replication slots will also keep PostgreSQL from
deleting WAL segments.

> However, I could not find an explicit statement about whether taking or c=
ompleting a
> base backup itself affects when WAL segments in the local pg_wal director=
y become
> eligible for recycling/removal.
>=20
> Could the documentation explicitly clarify this relationship?=20

I don't think that there is a relationship between WAL recycling and a base=
 backup,
so there is nothing to document.

Yours,
Laurenz Albe