> it seems fairly unlikely to me that this would be useful enough to
> justify using up a precious hint bit. The applicability of the hint
> is very short-term --- as soon as the tuple is dead to all transactions,
> it can be marked with the existing LP_DEAD hint bit. And if it's only
> useful for uniqueness checks, as seems to be the case, that's another
> big restriction on the value.
>
> Right. It is of little value.
Gokul.