In article <1115104938(dot)5853(dot)25(dot)camel(at)localhost(dot)localdomain>,
Ragnar Hafstað <gnari(at)simnet(dot)is> writes:
> 20 ms does not sound like a big problem.
> if 20 ms is really too much for you, and add_date IS a timestamp,
> you might think about adding a date column , maintained
> by triggers of by your application, and add an index on (user_id, x)
Maybe a functional index on "date_trunc('day', add_date)" would be helpful?