-- TODO: not working yet -- LEADING hint sets the order properly but not the ORDERED hint drop table t1; drop table t2; create table t1 as select * from all_objects; create table t2 as select * from all_objects; create index i1 on t2(object_id); exec dbms_stats.gather_table_stats(user,'T1'); exec dbms_stats.gather_table_stats(user,'T2'); -- ordered hint "ignored" starting from 11.2.0.1 thanks to distinct aggregation transformation select /*+ ORDERED */ t1.owner, count(distinct t2.object_type) from t2, t1 where t1.object_id = t2.object_id group by t1.owner; @x select /*+ ORDERED NO_TRANSFORM_DISTINCT_AGG */ t1.owner, count(distinct t2.object_type) from t2, t1 where t1.object_id = t2.object_id group by t1.owner; @x