Re: block-level incremental backup - Mailing list pgsql-hackers

From Andres Freund
Subject Re: block-level incremental backup
Date
Msg-id 20190410185551.2vngfp42ig4tgb4i@alap3.anarazel.de
Whole thread Raw
In response to Re: block-level incremental backup  (Robert Haas <robertmhaas@gmail.com>)
Responses Re: block-level incremental backup
List pgsql-hackers
Hi,

On 2019-04-10 14:38:43 -0400, Robert Haas wrote:
> On Wed, Apr 10, 2019 at 2:21 PM Jehan-Guillaume de Rorthais
> <jgdr@dalibo.com> wrote:
> > In my current design, the scan is done backward from end to start and I keep all
> > the records appearing after the last occurrence of their respective FPI.
> 
> Oh, interesting.  That seems like it would require pretty major
> surgery on the WAL stream.

Can't you just read each segment forward, and then reverse? That's not
that much memory? And sure, there's some inefficient cases where records
span many segments, but that's rare enough that reading a few segments
several times doesn't strike me as particularly bad?

Greetings,

Andres Freund



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