Fwd: Reversing flow of WAL shipping

From: David Jantzen <djantzen@ql2.com>

Date: October 21, 2009 8:52:59 PM PDT

To: "pgsql-general@postgresql.org" <pgsql-general@postgresql.org>

Subject: Reversing flow of WAL shipping

Hey Folks,

I want to run a warm standby scenario by you.  I'm pretty sure it'll  
work, but it's a very large database so even the slightest mistake can  
mean a major setback.

Scenario:

Server A is the provider node, shipping WAL files to Server B.  Server  
B is destined to become the provider node (newer hardware), and has a  
sibling Server C that will be the warm standby.

Here's the question: when I turn Server B into the production/provider  
node, it's going to switch into the next timeline.  If I then attempt  
to put Server A (or Server C) into recovery mode, will it switch to  
the new current timeline, or complain about being in the older  
timeline?  Do I have to take another full backup of Server B after  
it's become the production/provider node?

Thanks,
David