Re: MVCC, undo log, and HOT

Bruce Momjian wrote:
> Those who have been with the community from long ago might remember
> discussion about implementing a undo log.  The big advantage of this is
> that it allows UPDATE to _replace_ rows and limits the amount of cleanup
> required for UPDATEs.
> 
> I am hoping that with HOT we will no longer have any need to even
> consider undo.
> 

We were considering it?

I certainly wasn't.  I've enough experience with Oracle and InnoDB to 
see that an undo log is its own set of performance issues.   No thanks.

Hopefully the "multi-thread the backend" idea is dead, too.

--Josh