The verbose output shows the table being vacuumed last. Maybe it
changed after 8.0
Greg Stark wrote:
> Jim Nasby <decibel@decibel.org> writes:
>
>>> My RFE: When vacuuming a table, pg should try to vacuum the primary key
>>> first. If that results in 0 recovered entries, then assume the table has no
>>> updates/deletes and skip the rest of that table.
>
> That makes no sense. Vacuum starts by scanning the table itself, not the
> indexes. It only goes to the indexes after it has found tuples that need
> cleaning up. There's nothing to look at in the indexes that would tell it
> whether there are any tuples to clean up.
>
