On Wed, May 25, 2011 at 10:05 PM, Greg Stark <gsstark@mit.edu> wrote:
>> updated_density = old_density + (new_density - old_density) * reliability
>> new_reltuples = updated_density * new_relpages
>
> This amounts to assuming that the pages observed in the vacuum have
> the density observed and the pages that weren't seen have the density
> that were previously in the reltuples/relpages stats.
In case it's not clear, Tom's expression for updated_density is
equivalent by simple algebra to:
updated_density = (old_density * (1-reliability)) + (new_density * reliability)
--
greg
