-------------------------------------------------------------------------------- -- Author: Alberto Dell'Era -- Copyright: (c) 2008-2012 Alberto Dell'Era http://www.adellera.it -------------------------------------------------------------------------------- set echo on set trimspool on /* drop table t; create table t (x int, y int); create index t_x_idx on t(x); insert into t(x,y) select rownum, rownum from dual connect by level <= 10000; commit; exec dbms_stats.gather_table_stats(user, 'T', cascade=>true, method_opt=>'for all columns size 1', estimate_percent=>null); */ --alter system flush shared_pool; alter system flush buffer_cache; alter session set statistics_level=all; select /*+ index(t,t_x_idx) xplan_test_marker */ t.y, (select y from t t2 where t2.x = t.x) from t where x > 0; select /*+ leading(t2) use_nl(t1,t2) index(t2,t_x_idx) xplan_test_marker */ t1.*, t2.* from t t1, t t2 where t1.x = t2.x and t1.y <= 1000; update /*+ xplan_test_marker */ t set x = x; rollback; set autotrace traceonly statistics insert /*+ append xplan_test_marker */ into t select rownum-1, rownum-1 from dual connect by level <= 100000; rollback; set autotrace off @xplan "%xplan_test_marker%" "ti=n,oi=n,plan_details=y"