oracle--v$lock 字段详解

V$LOCK视图结构

列名	类型	字段说明
ADDR	RAW（4 | 8）	Address of lock state object
KADDR	RAW（4|8）	Address of lock
SID	NUMBER	会话的sid，可以和v$session 关联
TYPE	VARCHAR2(2)	区分该锁保护对象的类型（表4） TM – DML enqueue TX – Transaction enqueue UL – User supplied –我们主要关注TX和TM两种类型的锁 –UL锁用户自己定义的，一般很少会定义，基本不用关注 –其它均为系统锁，会很快自动释放，不用关注
ID1 ID2	NUMBER	ID1,ID2的取值含义根据type的取值而有所不同 对于TM 锁 ID1表示被锁定表的object_id 可以和dba_objects视图关联取得具体表信息，ID2 值为0 对于TX 锁 ID1以十进制数值表示该事务所占用的回滚段号和事务槽slot number号,其组形式: 0xRRRRSSSS,RRRR=RBS/UNDO NUMBER,SSSS=SLOT NUMBER ID2 以十进制数值表示环绕wrap的次数，即事务槽被重用的次数
LMODE	NUMBER	0 – none 1 – null (NULL) 2 – row-S (SS) 3 – row-X (SX) 4 – share (S) 5 – S/Row-X (SSX) 6 – exclusive (X)
REQUEST	NUMBER	同LMODE –大于0时，表示当前会话被阻塞，其它会话占有改锁的模式
CTIME	NUMBER	已持有或者等待锁的时间
BLOCK	NUMBER	是否阻塞其他会话锁申请 1:阻塞 0:不阻塞

TYPE 字段内含义：

System Type	Description	System Type	Description
BL	Buffer hash table instance	NA..NZ	Library cache pin instance (A..Z = namespace)
CF	Control file schema global enqueue	PF	Password File
CI	Cross-instance function invocation instance	PI, PS	Parallel operation
CU	Cursor bind	PR	Process startup
DF	datafile instance	QA..QZ	Row cache instance (A..Z = cache)
DL	Direct loader parallel index create	RT	Redo thread global enqueue
DM	Mount/startup db primary/secondary instance	SC	System change number instance
DR	Distributed recovery process	SM	SMON
DX	Distributed transaction entry	SN	Sequence number instance
FS	File set	SQ	Sequence number enqueue
HW	Space management operations on a specific segment	SS	Sort segment
IN	Instance number	ST	Space transaction enqueue
IR	Instance recovery serialization global enqueue	SV	Sequence number value
IS	Instance state	TA	Generic enqueue
IV	Library cache invalidation instance	TS	Temporary segment enqueue (ID2=0)
JQ	Job queue	TS	New block allocation enqueue (ID2=1)
KK	Thread kick	TT	Temporary table enqueue
LA .. LP	Library cache lock instance lock (A..P = namespace)	UN	User name
MM	Mount definition global enqueue	US	Undo segment DDL
MR	Media recovery	WL	Being-written redo log instance

此表使用相关锁脚本：

select a.sid,b.serial#,
decode(a.type,
'TM',c.object_name,
NULL) OBJECT_NAME,
        decode(a.lmode,
                        0,'0:none',
                        1,'1:NULL',
                        2,'2:SS(Row-Share)',
                        3,'3:SX(Row-X)',
                        4,'4:S(Share)',
                        5,'5:SSX(S/Row-X)',
                        6,'6:X(Exclusive)') lmode,
        decode(a.REQUEST,
                        0,'0:none',
                        1,'1:NULL',
                        2,'2:SS(Row-Share)',
                        3,'3:SX(Row-X)',
                        4,'4:S(Share)',
                        5,'5:SSX(S/Row-X)',
                        6,'6:X(Exclusive)')  REQUEST,
                        a.ctime,a.block 
        from v$lock a,v$session b ,dba_objects c where b.sid=a.sid and  c.object_id(+)=a.id1;