Re: BUG #14109: pg_rewind fails to update target control file in one scenario

Michael Paquier wrote:
> On Thu, Apr 28, 2016 at 8:28 PM, Alvaro Herrera
> <alvherre@2ndquadrant.com> wrote:

> > Sounds to me like it should be enough to document (in pg_rewind's page)
> > that activating a slot prior to the promotion. Maybe we could have
> > "pg_ctl promote" have an option to create a slot, to make this simpler?
>
> That would be actually creating a slot before the last common
> checkpoint before promotion, which is a bit more tricky to evaluate.
> With luck, perhaps both of them would be on the same segment, but
> there is no way to be sure about that... It seems to me that what we
> are looking for here is a way to tell through
> pg_create_physical_replication_slot to reserve WAL from a position
> that caller has decided.

Well, that sounds like just a SMOP, doesn't it?

--
Álvaro Herrera                http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services