Subject: clarification for pg_basebackup and major versions

From: PG Doc comments form <[email-masked]>
Date: Mon, 29 Dec 2025 20:45:02 +0000

The following documentation comment has been logged on the website:

Page: https://www.postgresql.org/docs/18/app-pgbasebackup.html
Description:

Hi, Team !

Could we pls. clarify the following statement on the documentation page
https://www.postgresql.org/docs/18/app-pgbasebackup.html:
'pg_basebackup works with servers of the same or older major version, down
to 9.1.'

What does it exactly mean 'works with servers of the same or older major
version' ?

Most probably it means the possibility to use pg_basebackup binary of
version PG 17 to take backup of PG 14 server. Or something else ?

But it's definitely not ability to use pg_basebackup for PostgreSQL major
version upgrade, since pg_basebackup is not listed among the supported
options in https://www.postgresql.org/docs/18/upgrading.html

So, pls. let me propose two things:
- to clarify how pg_basebackup works with servers of the same or older major
version
- to clearly specify pg_basebackup cannot be used for PostgreSQL major
version upgrade

It could be done on the same page
https://www.postgresql.org/docs/18/app-pgbasebackup.html

Thanks !

best regards
Alexey Shishkin

---

From: "David G. Johnston" <[email-masked]>
Date: Wed, 31 Dec 2025 06:34:22 -0700

> - to clarify how pg_basebackup works with servers of the same or older

There is no “how”, it just does.  The documentation is versioned and “it”
means the binary produced by that version.

> - to clearly specify pg_basebackup cannot be used for PostgreSQL major

The page clearly states what a backup can be used for and upgrade is not
listed.

David J.

---

From: Alexey Shishkin <[email-masked]>
Date: Mon, 19 Jan 2026 19:01:57 +0100

Hi, Team !

Some more clarification about pg_basebackup which should be available in
the documentation:

- if pg_basebackup works between different versions of the same OS (ex.
RHEL8 and RHEL9)
- if pg_basebackup works between different types of OS Linux (ex. RHEL10
and Debian13) or OS Windows (ex. Windows 2016 and Windows 2019)
- if pg_basebackup works between different types of OS (ex. Ubuntu 24.04
and Windows 2022)
- if pg_basebackup works between different platforms (ex. Linux on amd64
and Linux on arm64)
- if pg_basebackup works between 32-bit OS and 64-bit OS

best regards,

Alexey Shishkin

*Alexey Shishkin*

Technical Account Manager

EDB Software GmbH

[email-masked]

www.enterprisedb.com <https://enterprisedb.com/>

---

From: "David G. Johnston" <[email-masked]>
Date: Mon, 19 Jan 2026 11:23:25 -0700

> - if pg_basebackup works between 32-bit OS and 64-bit OS
Please don’t top-post.

I agree this these dynamics aren’t readily exposed in the documentation.  I
disagree that pg_basebackup should be considered as an authoritative
location for covering the material.  It would simply link to such a
location in notes or “see also”.

In short, though, it like pretty much any client program will function
correctly regardless of differences with the server.  But a physical backup
is only truly promised to work if the environment that is processing the
data matches the environment that produced the data.

David J.

---

From: Alexey Shishkin <[email-masked]>
Date: Wed, 21 Jan 2026 10:04:42 +0100

Hi, Team !

Thanks for your reply !

What I see in the fields is the lack of such simple
supported/recommended/prerequisites notes/links in the official PostgreSQL
documentation (pg_backup is just an example).
That might lead to further confusion for PostgreSQL users.
As an example pls. let me share the logical replication documentation
https://www.postgresql.org/docs/current/logical-replication.html which says:
'
...
- Replicating between different major versions of PostgreSQL.
- Replicating between PostgreSQL instances on different platforms (for
example Linux to Windows)
...
'
I do believe something similar about pg_basebackup would be very welcome by
PostgreSQL users.

best regards,

Alexey Shishkin

*Alexey Shishkin*

EDB Software GmbH

On Mon, Jan 19, 2026 at 7:23 PM David G. Johnston <
[email-masked]> wrote:

> I agree this these dynamics aren’t readily exposed in the documentation.
> I disagree that pg_basebackup should be considered as an authoritative