以後看到一個記錄一個，不然老是忘記。

1、X$KSMSP

名稱含義為:
[K]ernal [S]torage [M]emory Management [S]GA Hea[P]，其中每一行都代表著shared pool中的一個chunk

KSMCHCOM是註釋欄位,每個記憶體塊被分配以後，註釋會新增在該欄位中.
x$ksmsp.ksmchsiz代表塊大小

x$ksmsp.ksmchcls列代表型別，主要有四類，說明如下:

free
Free chunks--不包含任何物件的chunk,可以不受限制的被分配.

recr
Recreatable chunks--包含可以被臨時移出記憶體的物件,在需要的時候，這個物件可以
被重新建立.例如,許多儲存共享sql程式碼的記憶體都是可以重建的.

freeabl
Freeable chunks--包含session週期或呼叫的物件,隨後可以被釋放.這部分記憶體有時候
可以全部或部分提前釋放.但是注意，由於某些物件是中間過程產生的，這些物件不能
臨時被移出記憶體(因為不可重建).

perm
Permanent memory chunks--包含永久物件.通常不能獨立釋放.

我們可以透過查詢x$ksmsp檢視來考察shared pool中存在的記憶體片的數量

2、x$bh

這個代表是BUFFER CACHE 中每一個塊的資訊。

欄位資訊如下：

The meaning of state:

0	FREE	no valid block image
1	XCUR	a current mode block, exclusive to this instance
2	SCUR	a current mode block, shared with other instances
3	CR	a consistent read (stale) block image
4	READ	buffer is reserved for a block being read from disk
5	MREC	a block in media recovery mode
6	IREC	a block in instance (crash) recovery mode

tch: tch is the touch count. A high touch count indicates that the buffer is used often. Therefore, it will probably be at the head of the MRU list. See also .

tim: touch time.

class represents a value designated for the use of the block.

lru_flag

set_ds maps to addr on .

le_addr can be outer joined on .le_addr.

flag is a bit array.

Bit	if set
0	Block is dirty
4	temporary block
9 or 10	ping
14	stale
16	direct
524288 (=0x80000)	Block was read in a	See

OBJ：應該就是OBJECT_ID。

x$kglpn
[K]ernel [G]eneric [L]ibrary [P]i[N]

dba_kgllock的基表

2.x$kglpn——[K]ernel [G]eneric [L]ibrary Cache Manager object [P]i[N]s

sys@ORALOCAL(192.168.0.22)> desc x$kglpn
##主要用來處理library cache pin holder

Name Null? Type
----------------------------------------------------- -------- ------------
ADDR RAW(4)
INDX NUMBER
INST_ID NUMBER
KGLPNADR RAW(4)
KGLPNUSE RAW(4)
KGLPNSES RAW(4)
KGLPNHDL RAW(4)
##關聯v$session_wait中event為library cache pin的P1RAW，再關聯v$session，可以查出sid和serial#

KGLPNLCK RAW(4)
KGLPNCNT NUMBER
KGLPNMOD NUMBER
##如果值為3，表示為library cache pin的holder；如果值為0，表示為waiter

KGLPNREQ NUMBER
##如果值為0，表示為library cache pin的holder；如果值為2，表示為waiter

KGLPNDMK NUMBER
KGLPNSPN NUMBER

x$kglob
[K]ernel [G]eneric [L]ibrary cache [OB]ject

x$kglob.kglhdadr = v$session_wait.p1raw

持續更新關於ORACLE X$檢視彙總

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