Re: pg_filedump 9.3: checksums (and a few other fixes)

On Wed, Jun 26, 2013 at 8:27 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> TBH, I've always been annoyed that pg_filedump is GPL and so there's no
> way for us to just ship it in contrib. (That stems from Red Hat
> corporate policy of a dozen years ago, but the conflict is real anyway.)
> If somebody is sufficiently excited about this topic to do something
> that's largely new anyway, I'd be in favor of starting from scratch so
> it could be put under the usual Postgres license.

Heroku are interested in online verification of basebackups (i.e.
using checksums to verify the integrity of heap files as they are
backed up, with a view to relying less and less on logical backups). I
am very glad that you made the page checksums stuff available to
external utilities in commit f04216341dd1cc235e975f93ac806d9d3729a344.

In the last couple of days, I haven't been able to figure out a way to
solve the problem of torn pages in a way that isn't a complete kludge
(with a hopefully-acceptable risk of false positives), so I've been
operating under the assumption that anything I produce here won't be
up to the standards of contrib. I had intended to release whatever
results as an open source project anyway. However, if we can figure
out a way to solve the torn pages problem, or at least produce
something acceptable, I think I'd certainly be able to find the time
to work on a contrib module that is mainly concerned with verifying
basebackups, but also offers some pg_filedump-like functionality.
That's something largely new.

--
Peter Geoghegan