Re: pg_basebackup, manifests and backends older than ~12

On 2020-Apr-13, Michael Paquier wrote:

> On Mon, Apr 13, 2020 at 11:52:51AM +0900, Kyotaro Horiguchi wrote:
> > Since I'm not sure about the work flow that contains taking a
> > basebackup from a server of a different version, I'm not sure which is
> > better between silently disabling and erroring out. However, it seems
> > to me, the option for replication slot is a choice of the way the tool
> > works which doesn't affect the result itself, but that for backup
> > manifest is about what the resulting backup contains. Therefore I
> > think it is better that pg_basebackup in PG13 should error out if the
> > source server doesn't support backup manifest but --no-manifest is not
> > specfied, and show how to accomplish their wants (, though I don't see
> > the wants clearly).
>
> Not sure what Robert and other authors of the feature think about
> that. What I am rather afraid of is somebody deciding to patch a
> script aimed at working across multiple backend versions to add
> unconditionally --no-manifest all the time, even for v13. That would
> kill the purpose of encouraging the use of manifests.

I agree, I think forcing users to specify --no-manifest when run on old
servers will cause users to write bad scripts; I vote for silently
disabling checksums.

--
Álvaro Herrera https://www.2ndQuadrant.com/
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