Re: pg_start_backup and pg_stop_backup Re: Re: [COMMITTERS] pgsql: Make CheckRequiredParameterValues() depend upon correct

Heikki Linnakangas wrote:
> Bruce Momjian wrote:
> > Tom Lane wrote:
> >> Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com> writes:
> >>> Tom Lane wrote:
> >>>> If you aren't archiving then there's no guarantee that you'll still have
> >>>> a continuous WAL series starting from the start of the backup.
> >>> I wasn't really thinking of this use case, but you could set
> >>> wal_keep_segments "high enough".
> >> Ah. Okay, that seems like a workable approach, at least for people with
> >> reasonably predictable WAL loads. We could certainly improve on it
> >> later to make it more bulletproof, but it's usable now --- if we relax
> >> the error checks.
> >>
> >> (wal_keep_segments can be changed without restarting, right?)
> >
> > Should we allow -1 to mean "keep all segments"?
>
> Umm, you can't keep all segments around forever, can you? Surely you
> have to recycle them sooner or later or you will run out of disk space.
>
> I guess you could move that responsibility to a user-written script, but
> we haven't traditionally encouraged or supported people to mess with the
> contents of pg_xlog. That would require some more thinking IMHO, not 9.0
> material.
>
> In practice, you can just set wal_keep_segments to some ridiculously
> high value to achieve the same result.

Which is where my 'wal_keep_segments = -1' idea came from.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com