v$session_wait的等待事件结束后,v$session_event的统计信息将会发生改变。 v$session_wait的统计信息意义不大,因为信息是实时变化的。 当v$session_wait里面的等待事件结束时,v$session_wait中的seconds_in_wait字段值被复制到v$session_event中time_waited字段,而v$session_event视图的average_time字段同时也被修改。 ...
单个等待-(在GV$SESSION_WAIT中看到的等待) P1 File# : Oracle请求读取的文件的file#。 P2 Block#: Oracle文件中开始读取块的起始块号 P3 描述等待产生原因的类别,比如Mode requested/mode held/block class SECONDS_IN_WAIT: 等待当前事件的时间,包括网络延迟和慢速服务时间 如果等待缓冲区的时间很长,那么需要按...
The term "seconds in wait" means the number of seconds that a SQL Statement, Database User, etc. was waiting on an event. It is possible that the total number of "seconds in wait" exceeds the total amount of time in the period. The following example will illustrate how this occurs. E...
在state是waiting的情况下,log file parallel等待的seq#都是35693,但是seconds_in_wait达到了21秒。简单来说,就是lgwr进程写一个IO需要21秒! 至此,我们可以肯定,IO子系统有问题,需要重点排查IO路径下的光纤线、SAN交换机、存储的报错和性能情况。 2.8 如何进一步证明IO路径环节有问题(跨部门合作) 考虑到客户那边管...
SQL>selectsid,p1raw,p2,p3,seconds_in_wait,wait_time,statefromv$session_waitwhereevent='latch: cache buffers chains'order by3,2; 使用P1RAW=00000300DA316800为例子进行关联热快对象。 SQL>selecta.hladdr,a.file#,a.dbablk,a.tch,a.obj,b.object_namefromx$bh a, dba_objects bwhere(a.obj = ...
Seconds_in_wait :表示等待持续的时间信息Eve nt:表示会话等待的事件,锁等于en queuedba_locks对v$lock的格式 化视图。Session_id :和 v$lock 中的 Sid 对应。 Lock_type :和 v$lock 中的 type 对应。Lock_ID1 :和 v$lock 中的 ID1 对应。Mode_held,mode_requested :和 v$lock 中的 Imodejequest 相...
在state是waiting的情况下,节点1 log file parallel等待的seq#都是35693,但是seconds_in_wait达到了21秒。简单来说,就是lgwr进程写一个IO需要21秒! 这意味着,压测时所有并发进程必须要发生等待,等lgwr进程完成这个的IO,才可以继续通知LGWR进程帮忙刷log buffer的改变向量,因此从压测的TPS曲线来看,就是不稳定,出现了...
select sid, event, p1, p2, p3, WAIT_TIME, SECONDS_IN_WAIT from v$session_wait where event not like 'SQL%' and event not like 'rdbms%'; 说明:如果数据库长时间持续出现大量像latch free,enqueue,buffer busy waits,db file sequential read,db file scattered read等等待事件时,需要对其进行分析,可...
The term "seconds in wait" means the number of seconds that a SQL Statement, Database User, etc. was waiting on an event. It is possible that the total number of "seconds in wait" exceeds the total amount of time in the period. The following example will illustrate how this occurs. ...
s.seconds_in_wait SIW, s.seq#FROMv$sessions, v$process pWHEREp.addr = s.paddrAND( s.programLIKE'%MRP%'ORs.programLIKE'%PR0%'ORs.programLIKE'%DBW%'ORs.programLIKE'%CKPT%')orderbys.process / 指定并行度恢复(on standby) alterdatabaserecover managed standbydatabaseparallel8disconnectfromsess...