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