22.Oracle杂记——Oracle常用动态视图v$lock

视图v$lock：通过访问数据库会话，设置对象锁的所有信息

描述如下：

sys@PDB1> desc v$lock;

Name Null? Type

------------------------------------------------------------- ------------------------------------

ADDR RAW(8)

KADDR RAW(8)

SID NUMBER

TYPE VARCHAR2(2)

ID1 NUMBER

ID2 NUMBER

LMODE NUMBER

REQUEST NUMBER

CTIME NUMBER

BLOCK NUMBER

CON_ID NUMBER

各个列描述如下：

ADDR：锁定状态对象的地址

KADDR：锁的地址

SID ：保持或获取锁的会话ID

TYPE：用户或系统锁的类型（用户类型：TM,TX,UL；系统类型见后面单独描述。）

ID1 ：锁的参数1

ID2：锁的参数2

LMODE：会话拥有锁的模式（0,1,2,3,4,5,6,）

REQUEST：进程请求锁的模式（0,6，）

CTIME：当前模式批准的时间

BLOCK：是否阻塞其他进程

CON_ID：数据持有的容器ID。

注意：其中TYPE列中，关于系统类型有如下：

System　Type Description
AEEdition enqueue

MR Media recovery
ATLock held for the ALTER TABLE statement

NA..NZ Library cache pin instance (A..Z = namespace)
BLBuffer hash table instance

PF Password File
CFControl file schema global enqueue

PI,PS Parallel operation
CICross-instance function invocation instance

PR Process startup
CUCursor bind

QA..QZ Row cache instance (A..Z = cache)
DFdatafile instance

RT Redo thread global enqueue
DLDirect loader parallel index create

SC System change number instance
DMMount/startup db primary/secondary instance

SM SMON
DRDistributed recovery process

SN Sequence number instance
DXDistributed transaction entry

SQ Sequence number enqueue
FSFile set

SS Sort segment

HW Space management operations on aspecificsegment
STSpace transaction enqueue
INInstance number

SV Sequence number value
IRInstance recovery serialization global enqueue

TA Generic enqueue
ISInstance state

TS Temporary segment enqueue (ID2=0)
IVLibrary cache invalidation instance

TS New block allocation enqueue (ID2=1)
JQJob queue

TT Temporary table enqueue
KKThread kick

UN User name
LA.. LP Library cache lock instance lock (A..P =namespace)
USUndo segment DDL
MMMount definition global enqueue

WL Being-written redo log instance