library cahce pin(库高速缓存pin)等待事件与库高速缓存并发性有关,当会话尝试在库高速缓存中钉住对象
以修改或检查该对象时产生该事件。会话必须获取(pin)以确保此时对象没有被其他会话更新。
当会话正在编译或分析PL/SQL过程和视图时,Oracle提交该事件。
library cache pin和library cache lock的并不是hard parse
create or replace procedure test_prc as
begin
insert into test1 select * from test1;
end;
SESSION SID=1执行该存储过程后,
SESSION SID=36去编译该过程
SQL> select sid,event from v$session_wait where event not like '%message%';
SID EVENT
---------- ----------------------------------------------------------------
1 db file scattered read
2 pmon timer
3 VKTM Logical Idle Wait
5 DIAG idle wait
8 DIAG idle wait
10 db file async I/O submit
12 log file parallel write
13 smon timer
18 Streams AQ: qmn coordinator idle wait
26 Streams AQ: qmn slave idle wait
28 Space Manager: slave idle wait
SID EVENT
---------- ----------------------------------------------------------------
32 Streams AQ: waiting for time management or cleanup tasks
36 library cache pin
37 Data file init write
14 rows selected.
SQL> col name format a30
SQL> select SESSION_ID,NAME,P1,P2,P3,WAIT_TIME,CURRENT_OBJ#,CURRENT_FILE#,CURRENT_BLOCK#
from v$active_session_history ash, v$event_name enm
where ash.event#=enm.event#
and SESSION_ID=36; 2 3 4
SESSION_ID NAME P1 P2 P3 WAIT_TIME CURRENT_OBJ# CURRENT_FILE# CURRENT_BLOCK#
---------- ------------------------------ ---------- ---------- ---------- ---------- ------------ ------------- --------------
36 library cache pin 737880368 737837676 65539 0 236 1 102139
36 library cache pin 737880368 737837676 65539 0 236 1 102139
36 library cache pin 737880368 737837676 65539 0 236 1 102139
36 library cache pin 737880368 737837676 65539 0 236 1 102139
36 library cache pin 737880368 737837676 65539 0 236 1 102139
36 library cache pin 737880368 737837676 65539 0 236 1 102139
36 library cache pin 737880368 737837676 65539 0 236 1 102139
36 library cache pin 737880368 737837676 65539 0 236 1 102139
36 library cache pin 737880368 737837676 65539 0 236 1 102139
36 library cache pin 737880368 737837676 65539 0 236 1 102139
36 library cache pin 737880368 737837676 65539 0 236 1 102139
SESSION_ID NAME P1 P2 P3 WAIT_TIME CURRENT_OBJ# CURRENT_FILE# CURRENT_BLOCK#
---------- ------------------------------ ---------- ---------- ---------- ---------- ------------ ------------- --------------
36 library cache pin 737880368 737837676 65539 0 236 1 102139
36 library cache pin 737880368 737837676 65539 0 236 1 102139
36 library cache pin 737880368 737837676 65539 0 236 1 102139
36 library cache pin 737880368 737837676 65539 0 236 1 102139
36 library cache pin 737880368 737837676 65539 0 236 1 102139
36 library cache pin 737880368 737837676 65539 0 236 1 102139
36 library cache pin 737880368 737837676 65539 0 236 1 102139
36 library cache pin 737880368 737837676 65539 0 236 1 102139
36 library cache pin 737880368 737837676 65539 0 236 1 102139
36 library cache pin 737880368 737837676 65539 0 236 1 102139
36 library cache pin 737880368 737837676 65539 0 236 1 102139
SQL> SQL> select name, PARAMETER1,PARAMETER2,PARAMETER3 from v$event_name where name='library cache pin';
NAME PARAMETER1 PARAMETER2 PARAMETER3
------------------------------ -------------------- -------------------- ------------------------------
library cache pin handle address pin address 100*mode+namespace
--通过查询V$SESSION_WAIT找出正在等待”library cache pin”的session
SQL> SELECT sid,
SUBSTR (event, 1, 30),
TO_CHAR(p1, 'xxxxxxxx') p1_16,
--P1RAW P1_16,
p2,
p3
FROM v$session_wait
WHERE wait_time = 0 AND event LIKE 'library cache pin%'; 2 3 4 5 6 7 8
SID SUBSTR(EVENT,1,30) P1_16 P2 P3
---------- ------------------------------------------------------------ --------- ---------- ----------
36 library cache pin 2bfb2930 737458808 3.3599E+14
--通过查询DBA_LOCK_INTERNAL和V$SESSION_WAIT,可得到与”library cache pin” 等待相关的object的名字
SQL> SELECT TO_CHAR (SESSION_ID, '999') sid,
SUBSTR (LOCK_TYPE, 1, 30) TYPE,
SUBSTR (lock_id1, 1, 23) Object_Name,
SUBSTR (mode_held, 1, 4) HELD,
SUBSTR (mode_requested, 1, 4) REQ,
lock_id2 Lock_addr
FROM dba_lock_internal
WHERE mode_requested <> 'None' AND mode_requested <> mode_held
AND session_id IN
(SELECT sid
FROM v$session_wait
WHERE wait_time = 0 AND event LIKE 'library cache pin%');
2 3 4 5 6 7 8 9 10 11 12 ;
SID TYPE OBJECT_NAME HELD REQ LOCK_ADDR
---- ------------------------------------------------------------ ---------------------------------------------- -------- -------- -------------------------
---------------
36 Table/Procedure/Type Definitio TEST.TEST_PRC None Excl 2BFB2930
SQL> SQL> select sid, P1RAW,P1TEXT ,event from v$session_wait where event not like '%message%';
SID P1RAW P1TEXT EVENT
---------- ---------------- ------------------------------ ----------------------------------------------------------------
1 0000000000000004 file# db file scattered read
2 0000000000000100 duration pmon timer
3 00 VKTM Logical Idle Wait
5 0000000000000005 component DIAG idle wait
8 0000000000000005 component DIAG idle wait
10 000000000000077A requests db file async I/O submit
12 0000000000000001 files log file parallel write
13 000000000000012C sleep time smon timer
18 00 Streams AQ: qmn coordinator idle wait
26 0000000000000001 Type Streams AQ: qmn slave idle wait
28 0000000000000001 Slave ID Space Manager: slave idle wait
SID P1RAW P1TEXT EVENT
---------- ---------------- ------------------------------ ----------------------------------------------------------------
32 00 Streams AQ: waiting for time management or cleanup tasks
36 000000002BFB2930 handle address library cache pin
37 00 Slave ID Space Manager: slave idle wait
14 rows selected.
SELECT s.sid, kglpnmod "Mode", kglpnreq "Req",p.kglpnhdl
FROM x$kglpn p, v$session s
WHERE p.kglpnuse=s.saddr
AND kglpnhdl='&P1RAW'
SQL> SELECT s.sid, kglpnmod "Mode", kglpnreq "Req",p.kglpnhdl
FROM x$kglpn p, v$session s
WHERE p.kglpnuse=s.saddr 2 3 ;
SID Mode Req KGLPNHDL
---------- ---------- ---------- --------
36 0 3 2BFB2930
1 2 0 2BFB2930
这里的kglpnhdl=p1_16
SID SUBSTR(EVENT,1,30) P1_16 P2 P3
---------- ------------------------------------------------------------ --------- ---------- ----------
36 library cache pin 2bfb2930 737458808 3.3599E+14
000000002BFB2930 16进制就是2BFB2930 转换为10进制就是737880368