Re: Synchronization levels in SR

On Wed, 2010-09-08 at 09:50 -0400, Robert Haas wrote:

> So that means we have to make sure that none of the effects of a
> transaction can be seen until WAL is fsync'd on the master AND the
> slave has acked.

Yes, that's right. And I like your example; one for the docs.

There is a slight complexity there: An application might connect to the
standby and see the changes made by the transaction, even though the
master has not yet been notified, but will be in a moment. I don't see
that as an issue though, but worth mentioning cos its just the
"Byzantine Generals" problem.

-- Simon Riggs           www.2ndQuadrant.comPostgreSQL Development, 24x7 Support, Training and Services