SQL> set autotrace traceonly explain


SQL> select e1.*, e2.* from emp e1, emp e2;

Execution Plan
--------------------------------------------------------------------------------

   0      SELECT STATEMENT Optimizer=CHOOSE (Cost=15 Card=196 Bytes=12544)
   1    0   MERGE JOIN (CARTESIAN) (Cost=15 Card=196 Bytes=12544)
   2    1     TABLE ACCESS (FULL) OF 'EMP' (Cost=1 Card=14 Bytes=448)
   3    1     SORT (JOIN) (Cost=14 Card=14 Bytes=448)
   4    3       TABLE ACCESS (FULL) OF 'EMP' (Cost=1 Card=14 Bytes=448)