Re: Condition to become the standby mode.

On Fri, Jul 26, 2013 at 11:55 PM, Andres Freund <andres(at)2ndquadrant(dot)com> wrote:
> On 2013-07-26 23:47:59 +0900, Fujii Masao wrote:
>> >> If this problem is solved, there is possible of that we can failback
>> >> by removing the all WAL record which is in pg_xlog before server
>> >> starts as the slave server.
>> >> ( And we also use "synchronous_transfer" which I'm proposing, I think
>> >> we can fail-back without taking full backup surely)
>> >
>> > I still have *massive* doubts about the concept. But anyway, if you want
>> > to do so, you should generate a backup label that specifies the startup
>> > location.
>>
>> Generating a backup label doesn't seem to be enough because there is
>> no backup-end WAL record and we cannot know the consistency point.
>
> Since 9.2 we allow generation of base backups from standbys, the
> infrastructure built for should be sufficient to pass the lsn at which
> consistency is achieved.

Yeah, right. I'd forgotten about that.

Regards,

--
Fujii Masao