ITAGAKI Takahiro <[EMAIL PROTECTED]> writes: > I'm thinking to add "the number of vacuumed tuples" to the message from > vacuum. The stats collector will subtract the value from n_dead_tuples > instead of setting it to zero. This is also needed if we want to make > some kinds of "partial" vacuum methods.
This seems awfully dangerous to me, because then you are operating on dead reckoning forever: there will be nothing that can correct an inaccurate rowcount estimate, and in practice that means it will diverge arbitrarily far from reality :-(, because of the inherent inaccuracies of the stats system. I think the risk of that is far worse than the relatively small (or at least bounded) error arising from tuples not seen by vacuum. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq