On K, 2005-07-13 at 16:08 +0800, Christopher Kings-Lynne wrote:
> Hi,
>
> Does PostgreSQL do the following optimisation:
>
> SELECT * FROM diary WHERE date = '2005-05-01' ORDER BY date;
>
> or in fact even better (for my situation)
>
> SELECT * FROM diary WHERE date BETWEEN '2005-05-01' AND '2005-05-01'
> ORDER BY date;
>
> Does it know that the input to the sort routine is already sorted and
> hence is a no-op?
Yes
try EXPLAIN ;)
--
Hannu Krosing <hannu(at)skype(dot)net>