Re: Proposal: Incremental Backup

On Wed, Jul 30, 2014 at 1:11 AM, Marco Nenciarini
<marco(dot)nenciarini(at)2ndquadrant(dot)it> wrote:
> "differential backup" is widely used to refer to a backup that is always
> based on a "full backup". An "incremental backup" can be based either on
> a "full backup" or on a previous "incremental backup". We picked that
> name to emphasize this property.

You can refer to this email:
http://www.postgresql.org/message-id/CABUevExZ-2NH6jxB5sjs_dsS7qbmoF0NOYpEEyayBKbUfKPbqw@mail.gmail.com

> As a first step we would have a simple and robust method to produce a
> file-level incremental backup.
An approach using Postgres internals, which we are sure we can rely
on, is more robust. A LSN is similar to a timestamp in pg internals as
it refers to the point in time where a block was lastly modified.

>>> It could also be used in 'refresh' mode, by allowing the pg_basebackup
>>> command to 'refresh' an old backup directory with a new backup.
>> I am not sure this is really helpful...
>
> Could you please elaborate the last sentence?
This overlaps with the features you are proposing with
pg_restorebackup, where a backup is rebuilt. Why implementing two
interfaces for the same things?
--
Michael