But it is possible to use multiple indexes on dates, and that is why the one at the 
bottom works, right?

Would a single index get used for

SELECT appointment
FROM the_table
WHERE 0 <> (date_mask &&  date_range);


Tom Lane wrote:


No, an index can be used for one or the other.  Since we don't yet have
bitmap combining of indexes, you don't get to apply two indexes in a
single query.  Even if you did, this would be relatively inefficient
since each index would return a whole lotta rows.

Why don't you just do the straightforward thing and look for

WHERE appointment_date >= 'some_date'
  AND appointment_date <= 'some-other-date'

AFAICS that solves the stated problem.  Maybe you were not being clear
about what you want?

                        regards, tom lane



---------------------------(end of broadcast)---------------------------
TIP 6: Have you searched our list archives?

http://archives.postgresql.org

Reply via email to