Re: Synchronization levels in SR

On Wed, Sep 8, 2010 at 10:07 PM, Robert Haas <robertmhaas@gmail.com> wrote:
> On Wed, Sep 8, 2010 at 8:30 AM, Fujii Masao <masao.fujii@gmail.com> wrote:
>>> And in any event, there is ALWAYS a window of
>>> time during which the client doesn't know the transaction has
>>> committed but other transactions can potentially see its effects.
>>
>> Yep. The problem here is that synchronous replication is likely to
>> make the window very big.
>
> So what?  If the correctness of your application depends on the
> *amount of time* this window lasts, it's already broken.  It seems
> like you're arguing that we should artificially increase lock
> contention to guard against possible race conditions in user
> applications.  That doesn't make any sense to me, so one of us is
> confused.

Yep ;) On second thought, the problem here is that the effects of
the transaction marked as committed but still waiting for replication
can disappear after failover.

Regards,

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