Re: Use of 'now' constant datatype in view to take advantage of partitioned table

Resent. As I could not see my mail in the mailing list after about two hours.

On Thursday, August 21, 2014 1:43 PM, Patrick Dung <patrick_dkt(at)yahoo(dot)com(dot)hk> wrote:

Hi Postgresql users,

I have a master table with two partition table (food_2013p, food_2014p).

I found that when I use SELECT + 'now' constant, constraint exclusion works, (it skipped the 2013 partition).

EXPLAIN ANALYZE
 SELECT *
   FROM food
 WHERE food.post_timestamp >= ('now'::date - interval '1 month')::date AND food.post_timestamp <= 'now'
  ORDER BY food.post_timestamp  DESC
 LIMIT 30;

But when I put the query inside view, 'now' is converted to the timestamp when I run the create view.
So the view becomes:
  WHERE food.post_timestamp >= ('2014-08-21'::date - '1 mon'::interval)::date AND food.post_timestamp <= '2014-08-21 13:38:29.642347'::timestamp without time zone

This is not dynamic.
When I use now(), the query will scan other partition tables. I know this is a restriction of partition on non-immutable function.

Would it be possible or a feature request to take advantage of the partition table with query like this?

Thanks and regards,
Patrick