Re: Plans for solving the VACUUM problem

"Mikheev, Vadim" wrote:
>
> > I think so too. I've never said that an overwriting smgr
> > is easy and I don't love it particularily.
> >
> > What I'm objecting is to avoid UNDO without giving up
> > an overwriting smgr. We shouldn't be noncommittal now.
>
> Why not? We could decide to do overwriting smgr later
> and implement UNDO then.

What I'm refering to is the discussion about the handling
of subtransactions in order to introduce the savepoints
functionality. Or do we postpone *savepoints* again ?

I realize now few people have had the idea how to switch
to an overwriting smgr. I don't think an overwriting smgr
could be achived at once and we have to prepare one by one
for it. AFAIK there's no idea how to introduce an overwriting
smgr without UNDO. If we avoid UNDO now when overwriting smgr
would appear ? I also think that the problems Andreas has
specified are pretty serious. I also have known the problems
and I've expected that people have the idea to solve it but
... I'm inclined to give up an overwriting smgr now.

regards,
Hiroshi Inoue