On Thu, May 28, 2015 at 4:08 AM, Naoya Anzai <nao-an...@xc.jp.nec.com> wrote:
> > 2. Page visibility rate of each table > There is no way to know how many page-bits are them of each tables stored > in their visibility maps. If we can show this information, then we will be > able to guess vacuum overhead for the table. For example, if this table is > a > very big table but page visibility rate is high, then we can advise > pg-users > that vacuum for this table will execute faster than they think by low I/O > overhead. > Furthermore, this information can also be used in order to inform pg-users > about "real" index-only-scan usability. > Isn't this already pg_class.relallvisible? Cheers, Jeff
