Re: vacuum, performance, and MVCC

On Sat, 24 Jun 2006, Mark Woodward wrote:

> I'm probably mistaken, but aren't there already forward references in
> tuples to later versions? If so, I'm only sugesting reversing the order
> and referencing the latest version.

I thought I understood your idea, but now you lost me again. I thought 
what you want is that the older heap tuple has a pointer to the 
newer one. Which it already has, it's called t_ctid.

Can you try to explain more carefully how the whole thing would work? 
What would an index tuple point to? What pointers would a heap tuple 
have? What would an index scan do to find the row version it's interested 
in? What exactly would an update do?

- Heikki