Oracle Database 10g Enterprise Edition Release 10.1.0.2.0 - Prod
PL/SQL Release 10.1.0.2.0 - Production
CORE    10.1.0.2.0      Production
TNS for 32-bit Windows: Version 10.1.0.2.0 - Production
NLSRTL Version 10.1.0.2.0 - Production

scott@orcl> EXECUTE DBMS_STATS.GATHER_TABLE_STATS(OWNNAME => 'SCOTT',TABNAME => 'EMP',ESTIMATE_PERCE
NT => 10, METHOD_OPT => 'FOR ALL COLUMNS SIZE 1', CASCADE => TRUE);

PL/SQL procedure successfully completed.

scott@orcl> EXECUTE DBMS_STATS.GATHER_TABLE_STATS(OWNNAME => 'SCOTT',TABNAME => 'DEPT',ESTIMATE_PERC
ENT => 10, METHOD_OPT => 'FOR ALL COLUMNS SIZE 1', CASCADE => TRUE);

PL/SQL procedure successfully completed.

scott@orcl> SELECT  /*+ USE_HASH(emp dept) */  emp.empno, dept.dname
  2  FROM EMP , DEPT
  3  WHERE  emp.deptno = dept.deptno
  4  and dept.deptno = 10
  5  /

     EMPNO DNAME
---------- --------------
      7782 ACCOUNTING
      7839 ACCOUNTING
      7934 ACCOUNTING


Execution Plan
----------------------------------------------------------
   0      SELECT STATEMENT Optimizer=ALL_ROWS (Cost=4 Card=5 Bytes=100
          )

   1    0   NESTED LOOPS (Cost=4 Card=5 Bytes=100)
   2    1     TABLE ACCESS (BY INDEX ROWID) OF 'DEPT' (TABLE) (Cost=1
          Card=1 Bytes=13)

   3    2       INDEX (UNIQUE SCAN) OF 'SYS_C005770' (INDEX (UNIQUE))
          (Cost=0 Card=1)

   4    1     TABLE ACCESS (FULL) OF 'EMP' (TABLE) (Cost=3 Card=5 Byte
          s=35)

The CBO knows better than you.