邹建大哥请进，汗死了，删除记录竟然昨夜到现在还没停止。12小时啦

1.你的记录很多么?2.执行下面的语句是否需要很长时间?select * from mail a
where exists(
    select * from mail where id<a.id and mail=a.mail)
3.执行下面的语句是否有错误信息?
  dbcc checkdb('mail')
  go
  use mail
  dbcc checktable('mail')
4.如果是执行这样的删除语句呢?
delete a
from mail a
left join(
select id=min(id),mail from mail group by mail
)b on a.id=b.id and a.mail=b.mail
where b.id is null