Re: Proposal: Incremental Backup

On Wed, Aug 6, 2014 at 9:04 AM, Simon Riggs <simon(at)2ndquadrant(dot)com> wrote:
>
> On 5 August 2014 22:38, Claudio Freire <klaussfreire(at)gmail(dot)com> wrote:
> Thinking some more, there seems like this whole store-multiple-LSNs
> thing is too much. We can still do block-level incrementals just by
> using a single LSN as the reference point. We'd still need a complex
> file format and a complex file reconstruction program, so I think that
> is still "next release". We can call that INCREMENTAL BLOCK LEVEL.

Yes, that's the approach taken by pg_rman for its block-level
incremental backup. Btw, I don't think that the CPU cost to scan all
the relation files added to the one to rebuild the backups is worth
doing it on large instances. File-level backup would cover most of the
use cases that people face, and simplify footprint on core code. With
a single LSN as reference position of course to determine if a file
needs to be backup up of course, if it has at least one block that has
been modified with a LSN newer than the reference point.

Regards,
--
Michael