Re: POC: Cleaning up orphaned files using undo logs

On Tue, May 21, 2019 at 1:18 PM Andres Freund <andres@anarazel.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