Re: POC: Cleaning up orphaned files using undo logs

On Tue, May 21, 2019 at 1:18 PM Andres Freund <andres(at)anarazel(dot)de> wrote:
> I think this needs to be split into some constituent parts, to be
> reviewable. Discussing 270kb of patch at once is just too much.

+1.

> > + {
> > + {"rollback_overflow_size", PGC_USERSET, RESOURCES_MEM,
> > + gettext_noop("Rollbacks greater than this size are done lazily"),
> > + NULL,
> > + GUC_UNIT_MB
> > + },
> > + &rollback_overflow_size,
> > + 64, 0, MAX_KILOBYTES,
> > + NULL, NULL, NULL
> > + },
>
> rollback_foreground_size? rollback_background_size? I don't think
> overflow is particularly clear.

The problem with calling it 'rollback' is that a rollback is a general
PostgreSQL term that gives no hint the proposed undo facility is
involved. I'm not exactly sure what to propose but I think it's got
to have the word 'undo' in there someplace (or some new term we invent
that is only used in connection with undo).

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company