Re: Controlling hot standby

On Fri, 2009-01-23 at 12:17 -0600, Kevin Grittner wrote:
> >>> Simon Riggs <simon(at)2ndQuadrant(dot)com> wrote:
> > There are considerable benefits to having it turned on during PITR
> >
> > Please read this to see why
> >
> http://wiki.postgresql.org/wiki/Hot_Standby#Dynamic_Control_of_Recovery
>
> Am I reading this right? What I get out of it is that users can
> connect to the database during recovery, like with psql or JDBC? Any
> user can query recovery completion status and progress, while a
> superuser can also step through transactions in various ways? Can the
> data in the database be queried while recovery is paused?

That's a big Yes to all of that. Exactly what all this is for.

> If I'm understanding this, and data can be queried during a pause, I
> can certainly see use cases for this; but it might be important to be
> able to start the recovery in a paused state to avoid going too far in
> the transaction stream before a connection can be established and
> recovery paused.

OK, that's a simple addition. Thanks for the suggestion.

I'll make it pause just after it changes state, so you can connect and
tell it to progress as far as you like.

--
Simon Riggs www.2ndQuadrant.com
PostgreSQL Training, Services and Support