delete a duplicate rows in a oracle table

for example here, user HR is having table emp,

HR@prod SQL>select * from emp;

 EMPID ENAME                       SAL     DEPTNO
---------- -------------------- ---------- ----------
 10005 palani                    54544         10
 10001 Scott Tiger                1000         40
 10002 Frank Naude                 500         20
 10003 rajesh                    21000        140
 10004 ramesh                     3500        220
 10005 suresh                    34567        123

6 rows selected.

to delete duplicate rows in empid column
in emp table
SQL>delete from emp where rowid not in
(select max(rowid) from emp
group by empid);

1 row deleted.

SQL>select * from emp;

 EMPID ENAME                       SAL     DEPTNO
---------- -------------------- ---------- ----------
 10001 Scott Tiger                1000         40
 10002 Frank Naude                 500         20
 10003 rajesh                    21000        140
 10004 ramesh                     3500        220
 10005 suresh                    34567        123


to delete the old duplicate row from the table
instead of max(rowid) replace min(rowid)
for example,

HR@prod SQL>insert into emp
values(10005,'palani',54544,10);

1 row created.

HR@prod SQL>select * from emp;

   EMPID ENAME                       SAL     DEPTNO
---------- -------------------- ---------- ----------
   10005 palani                    54544         10
   10001 Scott Tiger                1000         40
   10002 Frank Naude                 500         20
   10003 rajesh                    21000        140
   10004 ramesh                     3500        220
   10005 suresh                    34567        123

6 rows selected.

HR@prod SQL>delete from emp where rowid not in
(select min(rowid) from emp
  group by empid);

1 row deleted.

HR@prod SQL>select * from emp;

   EMPID ENAME                       SAL     DEPTNO
---------- -------------------- ---------- ----------
   10005 palani                    54544         10
   10001 Scott Tiger                1000         40
   10002 Frank Naude                 500         20
   10003 rajesh                    21000        140
   10004 ramesh                     3500        220


thanks,