On Thu, Jun 27, 2013 at 7:27 AM, Amit Kapila <amit.kapila@huawei.com> wrote:
> Now I can look into it further, I have still not gone through in detail
> about your new approach to calculate the reltuples, but I am wondering
> whether there can be anyway with which estimates can be improved with
> different calculation in vac_estimate_reltuples().
I think this is getting at the threshold question for this patch,
which is whether it's really making things better or just moving the
problems around. I mean, I have no problem accepting that the new
algorithm is (1) reasonably cheap and (2) better in some cases. But
if it's worse in other cases, which AFAICS hasn't been discussed, then
it's no good.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company