Re: Hot Standby remaining issues - Mailing list pgsql-hackers

From Heikki Linnakangas
Subject Re: Hot Standby remaining issues
Date
Msg-id 4B155FEA.8080500@enterprisedb.com
Whole thread Raw
In response to Re: Hot Standby remaining issues  (Simon Riggs <simon@2ndQuadrant.com>)
Responses Re: Hot Standby remaining issues  (Simon Riggs <simon@2ndQuadrant.com>)
List pgsql-hackers
Simon Riggs wrote:
> commit 02c3eadb766201db084b668daa271db4a900adc9
> Author: Simon Riggs <sriggs@ebony.(none)>
> Date:   Sat Nov 28 06:23:33 2009 +0000
> 
>     Added wal_standby_info GUC to turn RM_STANDBY_ID messages on/off.
>     Various comments added also.
> 

This patch makes it unsafe to start hot standby mode from a shutdown
checkpoint, because we don't know if wal_standby_info was enabled in the
master.

I still don't think we need the GUC. But for future-proofing, perhaps we
should add a flag to shutdown checkpoint records, indicating whether
it's safe to start hot standby from it. That way, if we decide to add a
GUC like that at a later stage, we don't need to change the on-disk format.

--  Heikki Linnakangas EnterpriseDB   http://www.enterprisedb.com


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