        官网对oracle deadlock的说明
       http://docs.oracle.com/cd/E11882_01/server.112/e40540/consist.htm#CNCPT1339

        关于oracle lock介绍，参考下面的链接
  http://blog.itpub.net/28697282/viewspace-1484385/

什么是deadlock
        官方给出的说法是
         A deadlock is a situation in which two or more users are waiting for data locked by each other. Deadlocks prevent some transactions from continuing to work.
      死锁是两个或者多个用户等待被对方锁定的数据的情况。也就是说两个或者多个用户互相等待对方所占有的资源的情况。

deadlock的形成



deadlock的检测

        Oracle Database automatically detects deadlocks and resolves them by rolling back one statement involved in the deadlock, releasing one set of the conflicting row locks. The database returns a corresponding message to the transaction that undergoes statement-level rollback. The statement rolled back belongs to the transaction that detects the deadlock. Usually, the signalled transaction should be rolled back explicitly, but it can retry the rolled-back statement after waiting.
      oracle 自动检测并解决deadlock，通过回滚deadlock中相关的

与deadlock相关的进程（11g)
      与oracle deadlock相关的进程官网说明
       http://docs.oracle.com/cd/E11882_01/server.112/e40402/bgprocesses.htm#REFRN104

      下面是11g特有的检测死锁的两个进程 dia0，lmd0

Name	Expanded Name	Short Description	Long Description	External Properties
DIA0	Diagnostic Process	Detects and resolves hangs and deadlocks		ASM and Database instances
LMD0	Global Enqueue Service Daemon 0 Process	Manages incoming remote resource requests from other instances	LMD0 processes enqueue resources managed under Global Enqueue Service. In particular, LMD0 processes incoming enqueue request messages and controls access to global enqueues. It also performs distributed deadlock detections.	Database and ASM instances, Oracle RAC

deadlock模拟

ITPub博客

oracle deadlock 之（二）--deadlock 介绍

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