Re: backup manifests - Mailing list pgsql-hackers

From Robert Haas
Subject Re: backup manifests
Date
Msg-id CA+TgmoY3=+DVAQwBhigjGG8r3+jh3+7n_7ONAr6_DtVEOB1ssg@mail.gmail.com
Whole thread Raw
In response to Re: backup manifests  (Andres Freund <andres@anarazel.de>)
Responses Re: backup manifests  (Andres Freund <andres@anarazel.de>)
List pgsql-hackers
On Mon, Mar 30, 2020 at 2:59 PM Andres Freund <andres@anarazel.de> wrote:
> I wonder if it'd not be best, independent of whether we build in this
> verification, to include that metadata in the manifest file. That's for
> sure better than having to build a separate tool to parse timeline
> history files.

I don't think that's better, or at least not "for sure better". The
backup_label going to include the START TIMELINE, and if -Xfetch is
used, we're also going to have all the timeline history files. If the
backup manifest includes those same pieces of information, then we've
got two sources of truth: one copy in the files the server's actually
going to read, and another copy in the backup_manifest which we're
going to potentially use for validation but ignore at runtime. That
seems not great.

> Btw, just in case somebody suggests it: I don't think it's possible to
> compute the WAL checksums at this point. In stream mode WAL very well
> might already have been removed.

Right.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company



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