Re: [PATCHES] Infrastructure changes for recovery (v8)

On Tue, 2008-09-30 at 23:52 +0100, Simon Riggs wrote:
> * optional recovery_safe_start_location parameter now provided in
> recovery.conf, to allow a consistency point to be manually defined if a
> base backup was not taken using standard pg_start/stop backup functions

If using synchronous replication, it seems like this may be useful. For
instance, if the primary server A fails (let's assume power off
failure), then you make the secondary server B the new primary and start
committing transactions, and then you want to bring A back up as a
secondary to B.

Will server A know where to start recovering from, even if many
checkpoints have happened on server B in the meantime? Is there a way to
avoid wiping A and making a new base backup?

Are the safety issues that Heikki brought up potentially solvable, or am
I asking for the impossible?

And also, what if server A is shut down cleanly? Is there any way at all
to get it into recovery mode to catch up with B, or would it require a
new base backup?

I haven't read through the entire thread, so I apologize if this
question has been answered elsewhere.

Regards,
Jeff Davis