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Oracle Wait Events:checkpoint completed
作者：eygle |【转载时请以超链接形式标明文章出处和作者信息及本声明】链接：http://www.eygle.com/archives/2009/03/checkpoint_completed.html
今天帮用户恢复数据库，在关闭数据库时发现如下一个显著的等待事件：
WAIT #1: nam='checkpoint completed' ela= 4892320 p1=0 p2=0 p3=0
WAIT #1: nam='checkpoint completed' ela= 4892538 p1=0 p2=0 p3=0
WAIT #1: nam='checkpoint completed' ela= 4892539 p1=0 p2=0 p3=0
WAIT #1: nam='checkpoint completed' ela= 4892555 p1=0 p2=0 p3=0
WAIT #1: nam='checkpoint completed' ela= 4892541 p1=0 p2=0 p3=0
WAIT #1: nam='checkpoint completed' ela= 4892546 p1=0 p2=0 p3=0
WAIT #1: nam='checkpoint completed' ela= 4892549 p1=0 p2=0 p3=0
WAIT #1: nam='checkpoint completed' ela= 4892495 p1=0 p2=0 p3=0
WAIT #1: nam='checkpoint completed' ela= 4892542 p1=0 p2=0 p3=0
WAIT #1: nam='checkpoint completed' ela= 4892535 p1=0 p2=0 p3=0
WAIT #1: nam='checkpoint completed' ela= 1429367 p1=0 p2=0 p3=0
数据库可能在这个事件上花费大量的等待时间，这个事件没有参数表达：
SQL> SELECT NAME, parameter1, parameter2, parameter3
2 FROM v$event_name
3 WHERE NAME = 'checkpoint completed';
NAME PARAMETER1 PARAMETER2 PARAMETER3
-------------------- ---------- ---------- ----------
checkpoint completed
文档的解释如下：
checkpoint completed
A session waits for a checkpoint to complete.
This could happen, for example, during a close database or a local checkpoint.
Wait Time: 5 seconds
Parameters: None
也就是说，会话在等待检查点的完成，在数据库关闭、本地检查点发生时可能见到。
历史上的今天...
>> 2008-03-03文章:
>> 2006-03-03文章:
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这篇 【Oracle Wait Events:checkpoint completed】来自 eygle.com | CSDN网摘| del.icio.us|Google订阅 | 鲜果订阅 | 抓虾订阅
By eygle on 2009-03-03 10:58 | Comments (4) | Posted to FAQ | Edit |
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留言 (4)
然后呢？就没了？
你这文章写的 :(
Posted by: kamus at March 4, 2009 12:55 AM
同感. 打一棍子,吱一声.
Posted by: 木匠 at March 4, 2009 1:38 AM
同感. 打一棍子,吱一声.
我只是对"checkpoint completed"这个等待事件不感兴趣,所以没打一棍子. ^_^
Posted by: 木匠 at March 4, 2009 1:40 AM
这年头，还有多少人关心技术，测试一下，哈哈
Posted by: eygle at March 5, 2009 10:50 AM