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

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.

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com