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应用反映数据库慢，登陆实例和asm实例，反映都很慢，但是最后还是能登陆进去，最后登陆报如下错误：oracle@eedw1:/export/home/oracle $ ora siSQL*Plus: Release 11.2.0.3.0 Production on Thu Jan 4 20:45:19 2018Copyright (c) 1982, 2011, Oracle.  All rights reserved.ERROR:ORA-09925: Unable to crea...

http://blog.csdn.net/xujinyang/article/details/6829522Oracle的内存配置与oracle性能息息相关。关于内存的配置，是最影响Oracle性能的配置。内存还直接影响到其他两个重要资源的消耗：CPU和IO.  先看Oracle内存存储的主要内容是什么：程序代码（PLSQL、Java）；关于已经连接的会话的信息，...

brary cache lock、library cache pin原理分析：http://www.itpub.net/thread-1826347-1-1.htmlSQL>select name, parameter1, parameter2, parameter3 from v$event_name where name like '&event'; Enter value for event: library cache lockold   1: select name, parameter1, parameter2, parameter3 fr...

Buffer busy waits/read by other session从本质上讲，这个等待事件的产生仅说明了一个会话在等待一个Buffer（数据块），但是导致这个现象的原因却有很多种。常见的两种是：当一个会话试图修改一个数据块，但这个数据块正在被另一个会话修改时。当一个会话需要读取一个数据块，但这个数据块正在被另一个会话读取到内存中...

SQL> select name, parameter1, parameter2, parameter3 from v$event_name where name like '&event';Enter value for event: latch: shared poolold   1: select name, parameter1, parameter2, parameter3 from v$event_name where name like '&event'new   1: select name, parameter1, paramet...

参考：http://www.killdb.com/2015/07/13/%E5%85%B3%E4%BA%8Eenq-tx-row-lock-contention%E7%9A%84%E6%B5%8B%E8%AF%95%E5%92%8C%E6%A1%88%E4%BE%8B%E5%88%86%E6%9E%90.html关于enq: TX – row lock contention的测试和案例分析1、主键或唯一indexsession 1：SQL> select sid from v$mystat where rownum=1; &...

概述：enq: TX - index contention 这个等待事件解释如下： Waits for TX in mode 4 also occur when a transaction inserting a row in anindex has to wait for the end of an index block split being done by anothertransaction. This type of TX enqueue wait corresponds to the wait event enq: TX- inde...

SQL> l  1* select name, parameter1, parameter2, parameter3 from v$event_name where name like '&event'SQL> /Enter value for event: enq: TX - allocate ITL entryold   1: select name, parameter1, parameter2, parameter3 from v$event_name where name like '&event'new   1: sele...

SQL> l  1* select name, parameter1, parameter2, parameter3 from v$event_name where name like '&event'SQL> /Enter value for event: enq: TM - contentionold   1: select name, parameter1, parameter2, parameter3 from v$event_name where name like '&event'new   1: select name,...

SQL> l  1* select name, parameter1, parameter2, parameter3 from v$event_name where name like '&event'SQL> /Enter value for event: enq: SQ - contentionold   1: select name, parameter1, parameter2, parameter3 from v$event_name where name like '&event'new   1: select name,...

SQL> l  1* select name, parameter1, parameter2, parameter3 from v$event_name where name like '&event'SQL> /Enter value for event: enq: RO - fast object reuseold   1: select name, parameter1, parameter2, parameter3 from v$event_name where name like '&event'new   1: selec...

SQL> select name, parameter1, parameter2, parameter3 from v$event_name where name like '&event'; Enter value for event: enq: HW - contentionold   1: select name, parameter1, parameter2, parameter3 from v$event_name where name like '&event'new   1: select name, parameter1, para...

Pin S wait on X is usually due to high parses.  So check for high parsing sqls or tune application to share cursors.  For further diagnosis, please review following note ：Note:1349387.1  Trouble shooting 'Cursor: Pin S wait on X' wait通常是由于高分析。 所以检查高解析sqls或调整应用程...

Troubleshooting Steps：故障排除步骤"latch: cache buffers chains" contention is typically encountered because SQL statements read more buffers than they need to and multiple sessions are waiting to read the same block.通常会遇到"latch：cache buffers chains"争用，因为SQL语句读取的缓冲区比他们需...

http://blog.csdn.net/tianlesoftware/article/details/63056001. alter database datafile 'file_name' offline drop  该命令不会删除数据文件，只是将数据文件的状态更改为recover。 offline drop命令相当于把一个数据文件至于离线状态，并且需要恢复，并非删除数据文件。 数据文件的相关信息还会存在数据字典和...

session 1:SQL> select sid from v$mystat where rownum=1;       SID----------       148SQL> create or replace procedure pining    is    begin      null;    end;...

session1:SQL> select sid from v$mystat where rownum=1;       SID----------        41SQL> create or replace procedure pining    is    begin      null;    ...

此实验是在B库上恢复A库，不过更改了实例名。目标库只是按照到oracle软件为止。源库（A库）：  192.168.56.12 ORACLE_SID=DBdb DBID=3282897732目标库（B库）：192.168.56.28 ORACLE_SID=kill 源库备份（A库）联机全备：全被加控制文件及归档备份；run{backup database format '/home/oracle/BKdbfil...

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