Re: Keepalive for max_standby_delay

On Thu, Jun 3, 2010 at 5:00 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> I stand by my suggestion from yesterday: Let's define max_standby_delay
>> as the difference between a piece of WAL becoming available in the
>> standby, and applying it.
>
> My proposal is essentially the same as yours plus allowing the DBA to
> choose different max delays for the caught-up and not-caught-up cases.
> Maybe everybody will end up setting the two delays the same, but I think
> we don't have enough experience to decide that for them now.

Applying WAL that arrives via SR is not always the sign of the caught-up
or not-caught-up. OTOH, applying WAL restored from archive is not always
the sign of either of them. So isn't it nonsense to separate the delay in
order to control the behavior of a recovery for those cases?

Regards,

-- 
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center