Alvaro Herrera <alvherre(at)dcc(dot)uchile(dot)cl> writes:
> Would it be right to set the fast-root as true root during a VACUUM
> FULL? This would free all pages between true root and fast root.
Possibly okay, but why bother? It's hardly likely to free a meaningful
number of pages. And I think you'd need to invent another category of
WAL record to log the action, so the code overhead to make it happen
isn't trivial.
regards, tom lane