ORA-30009: Not enough memory for CONNECT BY operation

ORA-30009: Not enough memory for CONNECT BY operation
Cause: The memory size was not sufficient to process all the levels of the hierarchy specified by the CONNECT BY clause.
Action: In WORKAREA_SIZE_POLICY=AUTO mode, set PGA_AGGREGATE_TARGET to a reasonably larger value. Or, in WORKAREA_SIZE_POLICY=MANUAL mode, set SORT_AREA_SIZE to a reasonably larger value.

SQL> select count(*) from dual connect by level <= 100000000;
select count(*) from dual connect by level <= 100000000
                     *
ERROR at line 1:
ORA-30009: Not enough memory for CONNECT BY operation



SQL>select count(*) from
  2  (select level from dual connect by level <= 10000),
  3  (select level from dual connect by level <= 10000);

  COUNT(*)
----------
 100000000