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 一步一步在RHEL6.5+VMware Workstation 10上搭建 oracle 11gR2 rac + dg 之环境准备 （二）本篇目录结构： Linux 环境准备安装linux的环境，我就不介绍了，这一部分如果不会的童鞋就去百度吧，一百度一大堆，如果还是不会的话就直接下载我已经安装好的系统吧，下载下来直接可用（http://yunpan.cn/cg...

? ? ? 一步一步在RHEL6.5+VMware Workstation 10上搭建 oracle 11gR2 rac + dg ?之前传 （一）? ? ??2014年国庆放七天假，但对于我来说放不放假都一样，单身的我也不愿意多出去转转了，觉得没意思，看着人家一对一对的，我出去岂不是太煞风景，，，那做些什么好呢？那就搭...

1.1    简介     1.1.1    ASMLib     1.1.2    什么是 udev     1.1.3    Why ASMLIB and why not 1.2    在 RHEL 6.4 上安装 Oracle 11gR2 + AS...

一、Temporary Segments ConceptOracleoften requires temporary work space for intermediate stages of database processing. There are different kinds of temporary segments in the database.Some of them are created explicitly by the users. The others are created and accessed for the user by the system...

一、Oracle的缺省定时任务可能带来很多问题，所以我们有必要关注一下系统有哪些缺省的任务查询任务dba_scheduler_jobsdba_scheduler_job_run_details关闭任务execute dbms_scheduler.disable('AUTO_SPACE_ADVISOR_JOB');二、为了保证在RAC环境备份归档日志的方便性，归档日志除了分别在两节...

1. 故障概述2014年10月10日上午9点10分左右开始，营业厅等前端出现访问、业务办理等长时间无响应现象，定位业务访问相关数据库，为中心数据库RAC；通过排查，最终定位为某update语句对一上千万数据量的表进行全表扫描，造成大量的db file scattered read，引发数据库严重的IO性能问题，为造成此...

--查看event事件select event,count(*) cnt from DBA_HIST_ACTIVE_SESS_HISTORY where wait_class<>'Idle' and sample_time<sysdate-1group by event order by cnt ;--查看某时间段内的sqlSET PAUSE ONSET PAUSE 'Press Return To Continue'SET HEADING ONSET LINESIZE 300SET PAG...

在本文第一部分中，我们配置了一个物理备库。在这第二部分中，我将介绍主备切换(Switchover)，故障转移(Failover)，客户端故 障转移(Client Failover)，使用闪回数据库重建库，活动数据卫士(Active Data Guard)，还讨论了一点备份。故障转移配置现在你已经配好了一个物理备库，你可能想试试主备切换(switchover)...

oracle 由于impdp 引起的表统计信息被锁 ORA-20005: object statistics are locked发现一个用户下统计信息没有生成,查询user_tab_modifications 发现变动信息也超过10%没有警告日志执行exec dbms_stats.gather_schema_stats(ownname => 'test',granularity => 'ALL',cascade => true);还是没有生成然后执...

作为ORACLE DBA对SQL优化是必备的技能，常用的方法就是看执行计划，加hint或者修改SQL写法，但现实的工作中，往往修改应用的SQL是非常困难的，特别是 对电信、银行这个行业，修改应用程序过程十分繁杂，有没有办法不修改SQL就可以达到优化SQL执行计划的方法呢？答案是肯定的，从ORACLE 10g开始ORACLE提供了自动优化功能，...

1、创建services      srvctl add service -d <db_name> -s <service_name> -r "preferred-instance-list" -a "available-instance-list" -P <TFA-policy>      TFA-policy 选项为basic 或preconnect2、查看services配置      srvctl...

'log file sequential read' and 'log file single write'Both these Wait Events are I/O-related so they are likely to appear together with 'log file parallel write' if there is I/O contention on the redo logs. Follow the same guidelines for tuning them.'switch logfile command' ,'log file swi...

These Wait Events occur because of Buffer Cache operations involving the DBWR process(es) and I/O Slaves.'db file parallel write' , 'db file single write',  'write complete waits',  'free buffer waits' This wait shows up in database writer. DBW waits on "db file paral...

===========================================11g=====================================1) Stop Database Control, the listener and the database2) Disable Database Vault :Unix :cd $ORACLE_HOME/rdbms/libmake -f ins_rdbms.mk dv_off ioracleNote:In 11gR2 one can use chopt to disa...

--unplug pdbsalter pluggable database all close instances=all;alter pluggable database mypdb1 unplug into '/home/oracle/mypdb1.xml' instances=all;cp +DATA/MYDB/mypdb1/* +DATA/MYDB/mypdb2/drop pluggable database mypdb1 including datafiles;--plug pdbscp +DATA/MYDB/mypdb2...

list命令 可以用于查看对应文件的信息，backup,copy,archivelog等list incarnation===================================================list incarnation;list incarnation of database;list incarnation of database 'ORA9I';===================================================list backup=...

Sometimes it is necessary to move a Datafile to another Location (eg. Mountpoint, ASM Diskgroup,…) due to Space issues, Hardware Replacement or for Performance Reasons. There are several Possibilities to perform this Task explained below: Physical Standby Database is mounted:&nbs...

oracle@wodb1:/etc$more multipath.conf#### This is a template multipath-tools configuration file## Uncomment the lines relevent to your environment###defaults {# udev_dir /dev# polling_interval 10# path_selector "round-robin 0"# path_grouping_policy multibus#...

 select count(*),status from v$session group by status;select sql_id,event,count(*) from v$session where wait_class<>'Idle' group by sql_id,event order by 3;select sql_id,event,count(*) from v$session where wait_class<>'Idle' and event<>'SQL*Net message to client' group by sql_id...

--查找等待事件select inst_id,event,count(*) from gv$sessionwhere username is not nullgroup by inst_id,eventhaving count(*)>1order by 2,1;--分析执行计划explain plan for select * from tab;select * from table(dbms_xplan.display);--查询索引...