问查询占用100%的CPU，甚至在6小时后也没有完成

EN

select
    u.website,
    sum(e.ULVolume + e.DLVolume) as volume
from mytable e
left join mytable u on u.PID = e.PID and u.event ='update'
where e.Event = 'end'
group by 1;

*************************** 1. row ***************************
           id: 1   select_type: SIMPLE
        table: e
         type: ALL possible_keys: NULL
          key: NULL
      key_len: NULL
          ref: NULL
         rows: 2858631
        Extra: Using where; Using temporary; Using filesort
*************************** 2. row ***************************
           id: 1   select_type: SIMPLE
        table: u
         type: ALL possible_keys: NULL
          key: NULL
      key_len: NULL
          ref: NULL
         rows: 2858631
        Extra: 2 rows in set (0.00 sec)