Re: pgsql: Allow time delayed standbys and recovery

On 19 December 2013 19:19, Thom Brown <thom(at)linux(dot)com> wrote:
> On 12 December 2013 10:56, Simon Riggs <simon(at)2ndquadrant(dot)com> wrote:
>> Allow time delayed standbys and recovery
>>
>> Set min_recovery_apply_delay to force a delay in recovery apply for commit and
>> restore point WAL records. Other records are replayed immediately. Delay is
>> measured between WAL record time and local standby time.
>>
>> Robert Haas, Fabrízio de Royes Mello and Simon Riggs
>> Detailed review by Mitsumasa Kondo
>
> Could a note be added about the additional disk space requirements for
> WAL on the standby? If one is delaying replay, WAL files created over
> the delayed period will build up in pg_xlog on the standby until
> they're consumed upon replay, so considerations about storing those
> additional files will need to be made. It may otherwise trip up
> anyone who, say, delays replay by 24 hours in a busy production
> environment, and finds they have run out of disk space and no longer
> have a valid standby.

Thanks Thom, good point. I will add a note to the docs.

--
Simon Riggs http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services