然后根据SID，在v$session_wait视图中通过以下SQL查询到阻塞事件：
select event,seconds_in_wait,state from v$session_wait where sid=
例如这里查询到的阻塞事件是：library cache lock。
然后在SYS用户下，通过以下SQL获得引起这个阻塞的源头语句：
select sql_text
from v$sqlarea
where (v$sqlarea.address, v$sqlarea.hash_value) in (
select sql_address, sql_hash_value
from v$session
where sid in (
select sid
from v$session a, x$kglpn b
where a.saddr = b.kglpnuse
and b.kglpnmod <> 0
and b.kglpnhdl in (select p1raw
from v$session_wait
where sid=
http://hi.baidu.com/ljm0211/item/4a8bbe45bb586ae2bcf45136
