发现网上很多锁检查脚本更新一个锁检查脚本：都有些不符合预期，自己写了一个：

set line 300

col "SQL" for a50

col "waiting sid" for 99999

col event for a35

col "Holder SQL" for a50

SELECT DISTINCT a.SID "waiting sid",---被阻塞会话SID

c.sql_text "SQL",---被阻塞会话执行sql

b.SID "blocking sid",---阻塞源会话SID

a.blocking_instance,---阻塞源实例id

b.serial#,---阻塞源会话serial#

b.event,---阻塞源等待时间

b.sql_id,---阻塞源sqlid

b.prev_sql_id,---阻塞源prev_sqlid

d.sql_text "Holder SQL" ---阻塞源SQL

FROM gv$session a,

v$session b,

gv$sql c,

v$sql d

WHERE a.blocking_session = b.SID

AND c.sql_id = a.sql_id

and b.blocking_session  is null

AND d.sql_id = NVL (b.sql_id, b.prev_sql_id);