一些有用的SQL

select * from v$license
--取得数据库目前的进程数
select count(*) from v$process
--取得进程数的上限
select value from v$parameter where name = 'processes'
--获取SID
select instance_name from v$instance
--
select sid,
       v$session.username 用户名,
       last_call_et 持续时间,
       status 状态,
       LOCKWAIT 等待锁,
       machine 用户电脑名,
       logon_time 开始登入时间,
       sql_text
from v$session, v$process, v$sqlarea
where paddr = addr
   and sql_hash_value = hash_value
   and status = 'ACTIVE'
   and v$session.username is not null
order by last_call_et desc