Oracle查询优化-删除名称重复的记录

用name相同的方法

DELETE FROM table_name a WHERE EXISTS (SELECT NULL FROM table_name b WHERE a.name = b.name

用rowid方法
据据Oracle带的rowid属性，进行判断，是否存在重复,语句如下：
查数据:

select * from table1 a where rowid !=(select   max(rowid) 
     from table1 b where a.name1=b.name1 and a.name2=b.name2)

删数据：

delete   from table1 a where rowid !=(select   max(rowid) 
     from table1 b where a.name1=b.name1 and a.name2=b.name2......)

2.group by方法