On Mon, May 23, 2011 at 1:01 PM, Maciek Sakrejda <msakrejda@truviso.com> wrote:
>> You're probably reading it wrong. The sort itself takes about 1 ms (just
>> subtract the numbers in "actual=").
>
> I thought it was cost=startup_cost..total_cost. That is not quite the
> same thing, since startup_cost is effectively "cost to produce first
> row", and Sort can't really operate in a "streaming" fashion (well,
> theoretically, something like selection sort could, but that's beside
> the point) so it needs to do all the work up front. I'm no explain
> expert, so someone please correct me if I'm wrong.
You are right.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
