徹底搞清楚library cache lock的成因和解決方法(6)

這裡，簡單的介紹一下X$KGLLK，這個基表儲存了庫快取中物件的鎖的資訊，它對於解決這類問題特別有用，其名稱的含義如下：
[K]ernel Layer
[G]eneric Layer
[L]ibrary Cache Manager ( defined and mapped from kqlf )
Object Locks
X$KGLLK - Object [L]oc[K]s

KGLNAOBJ 列包含了在librarky cache中的物件上執行命令的語句的前80個字元（其實從這裡我們也可以大大縮小範圍了）
X$KGLLK.KGLLKUSE 和 x$kgllk.KGLLKSES 對應於跟蹤檔案中的owner的值
X$KGLLK.KGLLKADR
X$KGLLK.KGLLKHDL 對應於跟蹤檔案中的handle的值(handle=C000000122E2A6D8)，也就是'library cache lock'的地址
X$KGLLK.KGLLKPNS 對應於跟蹤檔案中的session pin的值
X$KGLLK.KGLLKSPN對應於跟蹤檔案中的savepoint的值

我們再來看一下更全面的資訊：
SQL> set linesize 2000
SQL> select * from X$KGLLK where KGLLKHDL = 'C000000122E2A6D8' order by KGLLKSNM,KGLNAOBJ
2 /

ADDR INDX INST_ID KGLLKADR KGLLKUSE KGLLKSES KGLLKSNM KGLLKHDL KGLLKPNC KGLLKPNS KGLLKCNT KGLLKMOD KGLLKREQ KGLLKFLG KGLLKSPN KGLLKHTB KGLNAHSH KGLHDPAR KGLHDNSP USER_NAME KGLNAOBJ
---------------- ---------- ---------- ---------------- ---------------- ---------------- ---------- ---------------- ---------------- ---------------- ---------- ---------- ---------- ---------- ---------- ---------------- ---------- ---------------- ---------- ------------------------------ ------------------------------------------------------------
800003FB0007E4D0 33 2 C00000011A449E20 C000000109F02C68 C000000109F02C68 30 C000000122E2A6D8 00 00 0 0 2 0 463 C00000011A4BC350 3990848181 C000000122E2A6D8 1 PUBUSER CSNOZ629926699966
800003FB0007E5B0 34 2 C00000011A44A150 C000000108C99E28 C000000108C99E28 37 C000000122E2A6D8 00 00 1 3 0 0 179 C00000011A4BB328 3990848181 C000000122E2A6D8 1 PUBUSER CSNOZ629926699966

SQL> set linesize 100
SQL> l
1* select * from X$KGLLK where KGLLKHDL = 'C000000122E2A6D8' order by KGLLKSNM,KGLNAOBJ
SQL> /

ADDR INDX INST_ID KGLLKADR KGLLKUSE KGLLKSES KGLLKSNM
---------------- ---------- ---------- ---------------- ---------------- ---------------- ----------
KGLLKHDL KGLLKPNC KGLLKPNS KGLLKCNT KGLLKMOD KGLLKREQ KGLLKFLG
---------------- ---------------- ---------------- ---------- ---------- ---------- ----------
KGLLKSPN KGLLKHTB KGLNAHSH KGLHDPAR KGLHDNSP USER_NAME
---------- ---------------- ---------- ---------------- ---------- ------------------------------
KGLNAOBJ
------------------------------------------------------------
800003FB0007E4D0 33 2 C00000011A449E20 C000000109F02C68 C000000109F02C68 30
C000000122E2A6D8 00 00 0 0 2 0
463 C00000011A4BC350 3990848181 C000000122E2A6D8 1 PUBUSER
CSNOZ629926699966

800003FB0007E5B0 34 2 C00000011A44A150 C000000108C99E28 C000000108C99E28 37
C000000122E2A6D8 00 00 1 3 0 0
179 C00000011A4BB328 3990848181 C000000122E2A6D8 1 PUBUSER
CSNOZ629926699966

SQL>

上一個例子中我們主要藉助於X$KGLLK基表和event systemstate解決問題，那麼如果你不瞭解X$KGLLK基表，或者忘記了如何使用它，那也不要緊張，這裡再介紹一種常規的方法。

從system state 的轉儲資訊中，我們已經注意到PROCESS 28當前正在等待'library cache lock'。
'handle address'表示的就是正持有 PROCESS 28 程式所等待的library cache中的地址。

現在我們繼續在跟蹤檔案中查詢包含 'handle=c000000122e2a6d8' 字串的ORACLE PROCESS，也就是查詢blocking session的資訊，發現資訊如下：

PROCESS 26: ----------------阻塞其他會話的Oracle程式，這裡PROCESS 26對應了V$PROCESS中的PID的值 ----------------------------------------
SO: c000000109c831e0, type: 2, owner: 0000000000000000, flag: INIT/-/-/0x00
(process) Oracle pid=26, calls cur/top: c00000010b2774d0/c00000010b2774d0, flag: (0) -
int error: 0, call error: 0, sess error: 0, txn error 0
(post info) last post received: 17 24 6
last post received-location: ksusig
last process to post me: c000000109c840f8 25 0
last post sent: 751404 0 15
last post sent-location: ksasnd
last process posted by me: c000000109c836e8 1 6
(latch info) wait_event=0 bits=0
Process Group: DEFAULT, pseudo proc: c000000109eefda0
O/S info: user: ora9i, term: UNKNOWN, ospid: 20552 OSD pid info: Unix process pid: 20552, image: (TNS V1-V3)
----------------------------------------
SO: c0000001180b9510, type: 8, owner: c000000109c831e0, flag: INIT/-/-/0x00
(FOB) flags=2 fib ptr=162e1b48 incno=0 pending i/o cnt=0
----------------------------------------
SO: c0000001180b9458, type: 8, owner: c000000109c831e0, flag: INIT/-/-/0x00
(FOB) flags=2 fib ptr=162deb18 incno=0 pending i/o cnt=0
----------------------------------------
SO: c0000001180b8230, type: 8, owner: c000000109c831e0, flag: INIT/-/-/0x00
(FOB) flags=2 fib ptr=162de848 incno=0 pending i/o cnt=0
----------------------------------------
SO: c0000001180b7b00, type: 8, owner: c000000109c831e0, flag: INIT/-/-/0x00
(FOB) flags=2 fib ptr=162de578 incno=0 pending i/o cnt=0
----------------------------------------
SO: c000000108c99e28, type: 4, owner: c000000109c831e0, flag: INIT/-/-/0x00
c000000108c99e28 對應的就是V$SESSION 中的SADDR的值，透過這個資訊就可以找到blocking session的SID等資訊
(session) trans: c0000001169403c0, creator: c000000109c831e0, flag: (100041) USR/- BSY/-/-/-/-/-
DID: 0002-001A-0000007D, short-term DID: 0000-0000-00000000
txn branch: c00000011b825e18
oct: 0, prv: 0, sql: 800003fb0005f7b0, psql: c00000011fbe3f98, user: 50/PUBUSER
O/S info: user: report16, term: , ospid: 20550, machine: cs_dc02 program: (TNS V1-V3)
application name: SQL*Plus, hash value=3669949024
waiting for 'SQL*Net message from dblink' blocking sess=0x0 seq=3319 wait_time=0
driver id=28444553, #bytes=1, =0 -------------------
這裡，

#bytes 表示個server process透過database link傳送給另一個server process的位元組數（bytes）driver id 是一個10進位制數，我們需要把它轉化為16進位制數，然後就會發現它對應於我們透過event 10046中的相應的資訊：*** 2005-01-10 11:44:48.200
WAIT #1: nam='SQL*Net message from dblink' ela= 104397696 p1=675562835 p2=1 p3=0
WAIT #1: nam='SQL*Net message to dblink' ela= 4 p1=675562835 p2=1 p3=0

SQL> select to_char(675562835,'XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX') from dual;

TO_CHAR(675562835,'XXXXXXXXXXXXXX
---------------------------------
28444553

SQL>

temporary object counter: 0
----------------------------------------
SO: c00000011a4496b0, type: 51, owner: c000000108c99e28, flag: INIT/-/-/0x00
LIBRARY OBJECT LOCK: lock=c00000011a4496b0 handle=c00000012029f968 mode=N
call pin=0000000000000000 session pin=c00000011a44ad70
htl=c00000011a449720[c00000011a4baa78,c00000011a4baa78] htb=c00000011a4baa78
user=c000000108c99e28 session=c000000108c99e28 count=1 flags=[00] savepoint=173
LIBRARY OBJECT HANDLE: handle=c00000012029f968
namespace=CRSR flags=RON/KGHP/PN0/[10010000]
kkkk-dddd-llll=0000-0041-0041 lock=N pin=0 latch#=3
lwt=c00000012029f998[c00000012029f998,c00000012029f998] ltm=c00000012029f9a8[c00000012029f9a8,c00000012029f9a8]
pwt=c00000012029f9c8[c00000012029f9c8,c00000012029f9c8] ptm=c00000012029fa58[c00000012029fa58,c00000012029fa58]
ref=c00000012029f978[c0000001202a0068, c0000001202a0068] lnd=c00000012029fa70[c00000012029fa70,c00000012029fa70]
LIBRARY OBJECT: object=c00000012029f5c8
type=CRSR flags=EXS[0001] pflags= [00] status=VALD load=0
DEPENDENCIES: count=1 size=16
AUTHORIZATIONS: count=1 size=16 minimum entrysize=16
ACCESSES: count=1 size=16
DATA BLOCKS:
data# heap pointer status pins change
----- -------- -------- ------ ---- ------
0 c00000012029f8a8 c00000012029f288 I/P/A 0 NONE
6 c00000012029f6e8 c00000012029e7c8 I/-/A 0 NONE
----------------------------------------

。。。 。。。

----------------------------------------
SO: c00000011a44a150, type: 51, owner: c0000001169403c0, flag: INIT/-/-/0x00
////////////// X$KGLLK.KGLLKADR 對應於SO(SO: c00000011a44a150 //////////////
////////////// X$KGLLK.KGLLKUSE 和 x$kgllk.KGLLKSES 對應於owner的值(owner: c0000001169403c0)
LIBRARY OBJECT LOCK: lock=c00000011a44a150 handle=c000000122e2a6d8 mode=X
////////////// X$KGLLK.KGLLKADR 對應於SO 和 lock的值(SO: c00000011a44a150,lock=c00000011a44a150) //////////////
////////////// X$KGLLK.KGLLKHDL 對應於handle的值(handle=c000000122e2a6d8) ////////////////
call pin=0000000000000000 session pin=0000000000000000
////////////// X$KGLLK.KGLLKPNS 對應於session pin的值(session pin=0000000000000000) //////////////
htl=c00000011a44a1c0[c00000011a4bb328,c00000011a4bb328] htb=c00000011a4bb328
user=c000000108c99e28 session=c000000108c99e28 count=1 flags=[00] savepoint=179
user和session的值分別對應著x$kgllk.KGLLKUSE 和 x$kgllk.KGLLKSES，也對應於V$SESSION中阻塞其他會話的SADDR ////////////// X$KGLLK.KGLLKSPN對應於savepoint的值(savepoint=179) //////////////
LIBRARY OBJECT HANDLE: handle=c000000122e2a6d8
name=PUBUSER.CSNOZ629926699966
hash=eddf82b5 timestamp=01-08-2005 13:00:18 previous=NULL
namespace=TABL/PRCD/TYPE flags=KGHP/TIM/PTM/SML/[02000000]
kkkk-dddd-llll=0000-0709-0001 lock=X pin=X latch#=3
lwt=c000000122e2a708[c00000011a449e40,c00000011a449e40] ltm=c000000122e2a718[c000000122e2a718,c000000122e2a718]
pwt=c000000122e2a738[c000000122e2a738,c000000122e2a738] ptm=c000000122e2a7c8[c000000122e2a7c8,c000000122e2a7c8]
ref=c000000122e2a6e8[c000000122e2a6e8, c000000122e2a6e8] lnd=c000000122e2a7e0[c000000122e2a7e0,c000000122e2a7e0]
LOCK INSTANCE LOCK: id=LBcafc8485d0949f81
PIN INSTANCE LOCK: id=NBcafc8485d0949f81 mode=X release=F flags=[00]
LIBRARY OBJECT: object=c000000122e12f70
type=TABL flags=EXS/LOC/CRT[0015] pflags= [00] status=VALD load=0
DATA BLOCKS:
data# heap pointer status pins change
----- -------- -------- ------ ---- ------
0 c000000122e2a618 c000000122e13118 I/P/A 0 INSERT
3 c000000122e13178 0 -/P/- 1 NONE
8 c000000122e12c30 c000000122febdb8 I/P/A 1 UPDATE
9 c000000122e13090 0 -/P/- 1 NONE
10 c000000122e12ce0 c000000122acbc70 I/P/A 1 UPDATE
----------------------------------------

。。。 。。。

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