Re: Comments on Custom RMGRs

On Wed, 2022-05-11 at 15:24 +0100, Simon Riggs wrote:
> [PATCH: rmgr_001.v1.patch]
> 
> [PATCH: rmgr_002.v1.patch]

Thank you. Both of these look like good ideas, and I will commit them
in a few days assuming that nobody else sees a problem.

> It occurs to me that any use of WAL presumes that Checkpoints exist
> and do something useful. However, the custom rmgr interface doesn't
> allow you to specify any actions on checkpoint, so ends up being
> limited in scope. So I think we also need an rm_checkpoint() call -
> which would be a no-op for existing rmgrs.
> [PATCH: rmgr_003.v1.patch]

I also like this idea, but can you describe the intended use case? I
looked through CheckPointGuts() and I'm not sure what else a custom AM
might want to do. Maybe sync special files in a way that's not handled
with RegisterSyncRequest()?

Regards,
	Jeff Davis