Re: Sync Rep v19

On Sat, 2011-03-05 at 20:08 +0900, Fujii Masao wrote:
> On Sat, Mar 5, 2011 at 7:28 AM, Simon Riggs <simon@2ndquadrant.com> wrote:
> > Yes, that can happen. As people will no doubt observe, this seems to be
> > an argument for wait-forever. What we actually need is a wait that lasts
> > longer than it takes for us to decide to failover, if the standby is
> > actually up and this is some kind of split brain situation. That way the
> > clients are still waiting when failover occurs. WAL is missing, but
> > since we didn't acknowledge the client we are OK to treat that situation
> > as if it were an abort.
> 
> Oracle Data Guard in the maximum availability mode behaves that way?
> 
> I'm sure that you are implementing something like the maximum availability
> mode rather than the maximum protection one. So I'd like to know how
> the data loss situation I described can be avoided in the maximum availability
> mode.

This is important, so I am taking time to formulate a full reply.

-- Simon Riggs           http://www.2ndQuadrant.com/books/PostgreSQL Development, 24x7 Support, Training and Services