Rules on select

Hi,

I tried to create rule on a view. It should contain a WHERE clause.
Unfortunately it does not work:

a_4m=# CREATE RULE sharp_p1_rule AS ON SELECT TO sharp
a_4m-# WHERE part_key = 1
a_4m-# DO
a_4m-# INSTEAD SELECT * FROM sharp_p1;
ERROR: ON SELECT rule may not use OLD

a_4m=# CREATE RULE sharp_p1_rule AS ON SELECT TO sharp
a_4m-# WHERE NEW.part_key = 1
a_4m-# DO
a_4m-# INSTEAD SELECT * FROM sharp_p1;
ERROR: relation "*NEW*" does not exist

a_4m=# CREATE RULE sharp_p1_rule AS ON SELECT TO sharp
a_4m-# WHERE OLD.part_key = 1
a_4m-# DO
a_4m-# INSTEAD SELECT * FROM sharp_p1;
ERROR: ON SELECT rule may not use OLD

Is it my mistake, or some feature I did not find in the docs?

regards,

Mariusz