> > Imho we should follow the swing idea.
>
>
> Yes, thats one option. Though given a choice I would waste
> four bytes in the heap-page than inserting a new index entry.
No question about that. My point was, that it would mean wasting
the 2 (2 must be enough for a slot pointer) bytes on every heap tuple,
hot or not. And then the decision is not so obvious anymore.
If you don't have the room for the back pointer on every slot,
there is no room to add one later.
Andreas