How does one eliminate duplicates rows from a table?

Choose one of the following queries to identify or remove duplicate rows from a table leaving only unique records in the table:

Method 1:

SQL> DELETE FROM table_name A WHERE ROWID > (

2 SELECT min(rowid) FROM table_name B

3 WHERE A.key_values = B.key_values);

Method 2:

SQL> create table table_name2 as select distinct * from table_name1;

SQL> drop table_name1;

SQL> rename table_name2 to table_name1;

SQL> -- Remember to recreate all indexes, constraints, triggers, etc on table...

Method 3: (thanks to Dennis Gurnick)

SQL> delete from my_table t1

SQL> where exists (select 'x' from my_table t2

SQL> where t2.key_value1 = t1.key_value1

SQL> and t2.key_value2 = t1.key_value2

SQL> and t2.rowid > t1.rowid);