The example given has "Seq Scan on tenk1 (cost=0.00..458.00" in the example, but then says, "you will find out that tenk1 has 358 disk pages" and "the cost is estimated at 358 page reads". Shouldn't this be 458 disk page reads?
I couldn't see this already discussed on this list. Is there a URL that has the latest docs compiled from CVS?