注释：
这里通过 Oracle 查询锁之间的依赖关系 的SQL 查询生产环境锁；
所以特写如下SQL实现 Oracle 查找锁之间依赖关系的最源头SID (首先得到锁的SID)，再通过SID找sql查问题..
*** 思路 ***
1、证明有锁，需要满足v$session.BLOCKING_SESSION[阻塞会话的SID] IS NOT NULL and BLOCKING_SESSION_STATUS = 'VALID'条件；
2、阻塞会话的SID 不在 SID 中就是最源头的SID (首先得到锁的SID)；
3、注意：v$session单实例，gv$session 多节点；
SQL：
WITH LOCK_1 AS
( SELECT DISTINCT S.INST_ID, S.SID, S.BLOCKING_SESSION, S.LAST_CALL_ET
FROM GV$SESSION S
WHERE S.BLOCKING_SESSION IS NOT NULL
and BLOCKING_SESSION_STATUS = 'VALID' )
SELECT DISTINCT BLOCKING_SESSION
FROM LOCK_1
WHERE BLOCKING_SESSION NOT IN ( SELECT SID FROM LOCK_1);
--------------------------------------------------------------------------------
本文用到的2个字段：
V$SESSION displays session information for each current session.
| Column | Datatype | Description |
|---|---|---|
| SID | NUMBER | Session identifier |
| BLOCKING_SESSION_STATUS | VARCHAR2(11) | This column provides details on whether there is a blocking session: VALID - there is a blocking session, and it is identified in the BLOCKING_INSTANCEand BLOCKING_SESSION columns NO HOLDER - there is no session blocking this session NOT IN WAIT - this session is not in a wait UNKNOWN - the blocking session is unknown |
| BLOCKING_SESSION | NUMBER | Session identifier of the blocking session. This column is valid only ifBLOCKING_SESSION_STATUS has the valueVALID. |
** SQL写的不是很智能，但能实现我的目的！ **