Jose Manuel Lorenzo Lopez <jose-manuel(dot)lorenzo-lopez(at)ica(dot)conti(dot)de> writes:
> I am using Postgresql 7.0.3!
Support for 'dow' in extract() is new in PG 7.1. Time to update.
Or use the underlying date_part function:
play=> select date_part('dow', now());
date_part
-----------
2
(1 row)
seems to work fine in 7.0 as well as 7.1.
regards, tom lane