Re: PITR, checkpoint, and local relations

On Thu, 2002-08-01 at 17:14, Bruce Momjian wrote:
> 
> J.R needs comments on this.  PITR has problems because local relations
> aren't logged to WAL.  Suggestions?
> 
I'm sorry if it wasn't clear. The issue is not that local relations
aren't logged to WAL, they are. The issue is that you can't checkpoint
them. That means if you need a lower bound on the LSN to recover from,
then you either need to wait for transactions using them all to commit
and flush their local buffers, or there needs to be a async way to tell
them all to flush.

I am working on a way to do this with a signal, using holdoffs around
calls into the storage-manager and VFS layers to prevent re-entrant
calls. The local buffer manager is simple enough that it should be
possible to flush them from within a signal handler at most times, but
the VFS and storage manager are not safe to re-enter from a handler.

Does this sound like a good idea?

-- 
J. R. Nield
jrnield@usol.com