Hi By testing this new 10g feature I noticed that even if a nested loop is = used, the join condition is not used as access predicate on the inner = table! To test it I used queries like the following one (based on the = sample schema SH provided by Oracle...). SELECT t.fiscal_month_number,=20 nvl(sum(s.amount_sold),0) amount_sold FROM sales s PARTITION BY (channel_id) RIGHT OUTER JOIN ( SELECT time_id, fiscal_month_number FROM times t WHERE t.fiscal_year =3D 1998 AND t.fiscal_quarter_number =3D 2 ) t USING (time_id) WHERE channel_id =3D 9 GROUP BY t.fiscal_month_number; The only way I found to workaround this problem is to add another join = to optimize the access to the inner table before doing the outer join, = i.e. something like this: SELECT t.fiscal_month_number,=20 nvl(sum(s.amount_sold),0) amount_sold FROM sales s PARTITION BY (channel_id) RIGHT OUTER JOIN ( SELECT time_id, fiscal_month_number FROM times t WHERE t.fiscal_year =3D 1998 AND t.fiscal_quarter_number =3D 2 ) t USING (time_id) JOIN times USING (time_id) WHERE channel_id =3D 9 AND t.fiscal_year =3D 1998 AND t.fiscal_quarter_number =3D 2 GROUP BY t.fiscal_month_number; Can somebody confirm or deny my observation? Thanks Chris -- //www.freelists.org/webpage/oracle-l