查询session status各项统计数据的前三名

select *

  from (select row_number() over(partition by a.STATISTIC# order by a.value desc) size_rank,

               a.sid,

               b.name,

               a.value

          from v$sesstat a,v$statname b,v$session c

          where c.STATUS='ACTIVE'

          and c.USERNAME is not null

          and a.sid=c.sid

          and a.STATISTIC#=b.STATISTIC#

         order by a.value desc)

 where size_rank <= 3

 and name like '%&NAME%'

 and sid like '%&SID%'

 order by name, size_rank;