"Zeugswetter Andreas DAZ SD" <ZeugswetterA@spardat.at> writes:
> The bgwriter could "update" all columns of dead heap tuples in heap
> pages
> to NULL and thus also gain free space without the need to touch the
> indexes.
> The slot would stay used but it would need less space.
Not unless it's running a transaction (consider TOAST updates).
regards, tom lane