The Vertica Database Forums

Thanks Sharon, the following worked ok:-
CREATE PROJECTION point_max_lastupdated_agg AS
SELECT instrument_id, element_id ,max(last_updated) AS max_timestamp FROM Phoenix1.Point
group by instrument_id, element_id
KSAFE;

select refresh('PHOENIX1.point');

select make_ahm_now();

Now to see if there are any performance improvements and it is used automatically.