系统有比较严重的LIBRARY CACHE PIN的等待，

Yong Huang

Even though there's no child latch named like '%library%', there could still be wait events named like that. Check v$latchname or v$system_event. I think this means those events don't involve those latches any more.

In addition, there's still one latch with 'library' in the name:

SQL> select name from v$latchname where name like '%library%';

NAME
-------------------------------------------
library cache load lock

It doesn't have children.

Yong Huang

bigacer

sundog315 发表于 2012-1-10 15:02
SQL> select * from v$version;
BANNER
----------------------------------------------------------- ...

在SID=60的SESSION上执行一个长查询的SQL

SQL> select distinct sid from v$mystat;
       SID
----------
        60
SQL> exec calling;
在SID=34的SESSION上修改session 60 procedure的一个SQL
SQL> select distinct sid from v$mystat;
       SID
----------
        34

SQL> create or replace PROCEDURE pining
    IS
    BEGIN
              NULL;
    END;
2    3    4    5    6  
/

SESSION 41上也执行存储过程
SQL> conn /as sysdba
Connected.
SQL> select distinct sid from v$mystat;
       SID
----------
        41
SQL> exec calling;

SESSION 52上也执行存储过程
SQL> select distinct sid from v$mystat;
       SID
----------
        52
SQL> exec calling;
select sid,event from v$session_wait;
34|library cache pin
41|library cache pin
52|library cache pin
60|PL/SQL lock timer