Re: testing hot standby

Jaime Casanova <jcasanov@systemguards.com.ec>

From: Jaime Casanova <jcasanov@systemguards.com.ec>
To: Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>
Cc: Fujii Masao <masao.fujii@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2010-04-13T16:08:08Z
Lists: pgsql-hackers
On Tue, Apr 13, 2010 at 11:06 AM, Heikki Linnakangas
<heikki.linnakangas@enterprisedb.com> wrote:
> Jaime Casanova wrote:
>>
>> i will read it on the morning and the thread where it is, something
>> that seems strange to me is that the patch touch twophase.c and
>> twophase.h, why?
>
> When you start hot standby from an online checkpoint, the XIDs of any
> two-phase transactions are included in the running-xacts record, just
> like any other in-progress transactions. At a shutdown checkpoint, we
> know that no regular transactions are in-progress, but there can be
> transactions in prepared state, which need to be considered as
> in-progress in the standby, but there's no information about them in the
> shutdown record. So we scan pg_twophase to discover them.
>
>

ah! that makes sense... thanks

-- 
Atentamente,
Jaime Casanova
Soporte y capacitación de PostgreSQL
Asesoría y desarrollo de sistemas
Guayaquil - Ecuador
Cel. +59387171157