Feedback-ID: ia2694551:Fastmail
Date: Mon, 20 Nov 2023 20:03:01 +0100
From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Dilip Kumar <dilipbalaut@gmail.com>,
	Andres Freund <andres@anarazel.de>,
 "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Subject: Re: trying again to get incremental backup
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On 2023-Nov-16, Robert Haas wrote:

> On Thu, Nov 16, 2023 at 12:23 PM Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:

> > I don't understand this point.  Currently, the protocol is that
> > UPLOAD_MANIFEST is used to send the manifest prior to requesting the
> > backup.  You seem to be saying that you're thinking of removing support
> > for UPLOAD_MANIFEST and instead just give the LSN as an option to the
> > BASE_BACKUP command?
> 
> I don't think I'd want to do exactly that, because then you could only
> send one LSN, and I do think we want to send a set of LSN ranges with
> the corresponding TLI for each. I was thinking about dumping
> UPLOAD_MANIFEST and instead having a command like:
> 
> INCREMENTAL_WAL_RANGE 1 2/462AC48 2/462C698
> 
> The client would execute this command one or more times before
> starting an incremental backup.

That sounds good to me.  Not having to parse the manifest server-side
sounds like a win, as does saving the transfer, for the cases where the
manifest is large.

Is this meant to support multiple timelines each with non-overlapping
adjacent ranges, rather than multiple non-adjacent ranges?

Do I have it right that you want to rewrite this bit before considering
this ready to commit?

-- 
Álvaro Herrera        Breisgau, Deutschland  —  https://www.EnterpriseDB.com/
"No nos atrevemos a muchas cosas porque son difíciles,
pero son difíciles porque no nos atrevemos a hacerlas" (Séneca)