Matthew <matthew@flymine.org> writes:
> Interesting thread. Now, I know absolutely nothing about how the data is
> stored, but it strikes me as being non-optimal that every single block on
> the disc needs to be written again just to update some hint bits. Could
> those bits be taken out into a separate bitmap stored somewhere else?
You are trying to optimize the wrong thing. Making vacuum cheaper at
the cost of making every tuple lookup more expensive is not going to
be a win.
regards, tom lane
