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关于锁的几个动态视图的总结

原创 IT综合 作者:litterbaby 时间:2007-07-11 09:27:51 0 删除 编辑
关于锁的几个动态视图的总结[@more@]

关于锁的几个动态视图的总结

v$lock

这个视图列出的是被Oracle数据库当前把持的锁。

ADDR

RAW(4 | 8)

Address of lock state object

KADDR

RAW(4 | 8)

Address of lock

SID

NUMBER

Identifier for session holding or acquiring the lock

TYPE

VARCHAR2(2)

Type of user or system lock

The locks on the user types are obtained by user applications. Any process that is blocking others is likely to be holding one of these locks. The user type locks are:

TM - DML enqueue

TX - Transaction enqueue

UL - User supplied

The locks on the system types are held for extremely short periods of time. The system type locks are listed in Table 6-1.

ID1

NUMBER

Lock identifier #1 (depends on type)

ID2

NUMBER

Lock identifier #2 (depends on type)

LMODE

NUMBER

Lock mode in which the session holds the lock:

  • 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

Lock mode in which the process requests the lock:

  • 0 - none
  • 1 - null (NULL)
  • 2 - row-S (SS)
  • 3 - row-X (SX)
  • 4 - share (S)
  • 5 - S/Row-X (SSX)
  • 6 - exclusive (X)

CTIME

NUMBER

Time since current mode was granted

BLOCK

NUMBER

A value of either 0 or 1, depending on whether or not the lock in question is the blocker.

v$resource

这个视图包含的是当前被锁的所有的资源名称和地址信息

ADDR

RAW(4 | 8)

Address of the resource object

TYPE

VARCHAR2(2)

Resource type; the resource types are listed in Table 6-1

ID1

NUMBER

Resource identifier #1

ID2

NUMBER

Resource identifier #2

v$locked_object

这个视图是一个诊断视图,可以从这个视图看到所有的当前系统上TM锁定(DML)的对象。提供了事务级的信息和用户操作系统级的信息和进程ID。

XIDUSN

NUMBER

Undo segment number

XIDSLOT

NUMBER

Slot number

XIDSQN

NUMBER

Sequence number

OBJECT_ID

NUMBER

Object ID being locked

SESSION_ID

NUMBER

Session ID

ORACLE_USERNAME

VARCHAR2(30)

Oracle user name

OS_USER_NAME

VARCHAR2(30)

OS user name

PROCESS

VARCHAR2(12)

OS process ID

LOCKED_MODE

NUMBER

Lock mode

还有几个视图是DBA视图:

dba_locks

这个视图和v$lock相似

SESSION_ID

NUMBER

Session holding or acquiring the lock

LOCK_TYPE

VARCHAR2(26)

Lock type

See Also: For a listing of lock types, see Appendix D, "Oracle Enqueue Names"

MODE HELD

VARCHAR2(40)

Lock mode

MODE REQUESTED

VARCHAR2(40)

Lock mode requested

LOCK_ID1

VARCHAR2(40)

Type-specific lock identifier, part 1

LOCK_ID2

VARCHAR2(40)

Type-specific lock identifier, part 2

LAST_CONVERT

NUMBER

The last convert

BLOCKING_OTHERS

VARCHAR2(40)

Whether the lock is currently blocking others

dba_dml_locks DML(TM)锁

dba_ddl_locks DDL锁

dba_waiters 等待和转换

dba_blockers 阻挡

可以使用utllockt.sql来显示锁的树。

关于锁的几个动态视图的总结

v$lock

这个视图列出的是被Oracle数据库当前把持的锁。

ADDR

RAW(4 | 8)

Address of lock state object

KADDR

RAW(4 | 8)

Address of lock

SID

NUMBER

Identifier for session holding or acquiring the lock

TYPE

VARCHAR2(2)

Type of user or system lock

The locks on the user types are obtained by user applications. Any process that is blocking others is likely to be holding one of these locks. The user type locks are:

TM - DML enqueue

TX - Transaction enqueue

UL - User supplied

The locks on the system types are held for extremely short periods of time. The system type locks are listed in Table 6-1.

ID1

NUMBER

Lock identifier #1 (depends on type)

ID2

NUMBER

Lock identifier #2 (depends on type)

LMODE

NUMBER

Lock mode in which the session holds the lock:

  • 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

Lock mode in which the process requests the lock:

  • 0 - none
  • 1 - null (NULL)
  • 2 - row-S (SS)
  • 3 - row-X (SX)
  • 4 - share (S)
  • 5 - S/Row-X (SSX)
  • 6 - exclusive (X)

CTIME

NUMBER

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