Re: block-level incremental backup

Greetings,

* Robert Haas (robertmhaas(at)gmail(dot)com) wrote:
> What I'm NOT willing to
> do is build a whole bunch of infrastructure that will help pgbackrest
> do amazing things but will not provide a simple and convenient way of
> taking incremental backups using only core tools. I do care about
> having something that's good for pgbackrest and other out-of-core
> tools. I just care about it MUCH LESS than I care about making
> PostgreSQL core awesome.

Then I misunderstood your original proposal where you talked about
providing something that the various external tools could use. If you'd
like to *just* provide a mechanism for pg_basebackup to be able to do a
trivial incremental backup, great, but it's not going to be useful or
used by the external tools, just like the existing base backup protocol
isn't used by the external tools because it can't be used in a parallel
fashion.

As such, and with all the other missing bits from pg_basebackup, it
looks likely to me that such a feature is going to be lackluster, at
best, and end up being only marginally interesting, when it could have
been much more and leveraged by all of the existing tools. I agree that
making a parallel-supporting protocol work is harder but I actually
don't think it would be *that* much more difficult to do.

That's frankly discouraging, but I'm not going to tell you where to
spend your time.

Making PG core awesome when it comes to backup is going to involve so
much more than just marginal improvements to pg_basebackup, but it's
also something that I'm very much supportive of and have invested a
great deal in, by spending time and resources working to build a tool
that gets closer to what an in-core solution would look like than
anything that exists today.

Thanks,

Stephen