Oracle 中删除多条一样的数据

delete abc where (c1,c2,c3) in (select c1,c2,c3 from abc group by c1,c2,c3 having count(*)>1) and rowid not in
(select min(rowid) from abc group by c1,c2,c3 having count(*)>1);

Oracle 中删除多条一样的数据（只剩下一条数据,根据伪列查询）；