On 2019-08-20 09:44:23 -0700, Andres Freund wrote:
> On 2019-08-20 21:02:18 +1200, Thomas Munro wrote:
> > Aside from code changes based on review (and I have more to come of
> > those), the attached experimental patchset (also at
> > https://github.com/EnterpriseDB/zheap/tree/undo) has a new protocol
> > that, I hope, allows for better concurrency, reliability and
> > readability, and removes a bunch of TODO notes about questionable
> > interlocking. However, I'm not quite done figuring out if the bufmgr
> > interaction is right and will be manageable on the undoaccess side, so
> > I'm hoping to get some feedback, not asking for anyone to rebase on
> > top of it yet.
> >
> > Previously, there were two LWLocks used to make sure that all
> > discarding was prevented while anyone was reading or writing data in
> > any part of an undo log, and (probably more problematically) vice
> > versa. Here's a new approach that removes that blocking:
Oh, more point I forgot to add: Cool!