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SQL是影响数据库性能的唯一手段。也是数据库优化最重要的部分。SQL语句并不是独立运行的，它需要在一定的场景下运行，同一个SQL在不同的场景下执行效率的效果可能完全不同。SQL语句在很大程度上要依靠索引、统计量的...

一.检查ASMLIB是否安装成功：检查驱动加载情况：[root@rhel1 disks]# lsmod | grep oracleasmoracleasm              84136  1检查oracleas...

转载自：http://kezizi.itpub.net/post/25895/229909As of today, Oracle 10gR2 RAC is not yet certified on SUSE10 platform. There are following things need to be taken care of when set it up:1. ipv6 sec...

http://blogs.oracle.com/simonthorpe/2009/06/configuring_oracle_asm_disks_i.htmlI was then able to mark my disks for ASM use, except I had already mounted these disks as part of my testing from earlie...

ORA-01843: not a valid month Cause: A date specified an valid month. Valid month are: January-December, for format code MONTH, and Jan-Dec, for format code MON. Action: Enter a valid month value i...

[oracle@blliu ~]$ sqlplus test/testSQL*Plus: Release 10.2.0.4.0 - Production on Sat Feb 27 13:27:07 2010Copyright (c) 1982, 2007, Oracle.  All Rights Reserved.Connected to:Oracle Database 10g ...

Metalink相关说明： The software requirements for HACMP 5.3 on 10gR2 are as follows:SoftwareVersion and other detailsAIX5.3 TL06 or newer (specifically bos.rte.lvm mus...

LANG是针对Linux系统的语言、地区、字符集的设置。NLS_LANG是针对Oracle语言、地区、字符集的设置。LANG=zh_CN.GB2312NLS_LANG=AMERICAN.AMERICA_ZHS16GBKLinux系统LANG设置：[root@blliu tmp]# localeLANG=zh_CN....

ASH (Active Session History)ASH以V$SESSION为基础，每秒采样一次，记录活动会话等待的事件。不活动的会话不会采样，采样工作由新引入的后台进程MMNL来完成。ASH buffers 的最小值为1MB,最大值不超过30MB。内存中记...

Linux内核：[root@centos VM]# uname -r2.6.18-164.el5[root@centos VM]# cat /etc/redhat-releaseCentOS release 5.4 (Final)Informatica PowerCenter文件：Informatica8.1.1_for_linux_x86.part1.rarInformatica8....

Linux版本：[root@centos sybaseiq]# cat /etc/redhat-releaseCentOS release 5.4 (Final)[root@centos sybaseiq]# uname -r2.6.18-164.el5执行加载报错：[root@centos mnt]# mount -t iso9660 -o loop /opt/soft/sy...

SCN (System Change Number )系统改变号一.SCN是Oracle中非常重要的时间机制。SQL> select timestamp_to_scn(sysdate) from dual;TIMESTAMP_TO_SCN(SYSDATE)-------------------------   &nbs...

一.下载地址：http://www.rpmfind.net/linux/rpm2html/search.php?query=unrar二.安装：[root@centos sybaseiq]# cat /etc/redhat-releaseCentOS release 5.4 (Final)[root@centos sybaseiq]# uname -r2.6.18-164....

转载自:http://icexiebin.itpub.net/post/28652/2661651.chechk init.oratimed_statistics=trueTOP查出最耗资源的PID2.SQL> select s.sid,s.serial# from v$session s,v$process pwhere s.paddr=p.addr and p.spid...

1.日期时间间隔操作 当前时间减去7分钟的时间 select sysdate,sysdate - interval '7' MINUTE from dual当前时间减去7小时的时间 select sysdate - interval '7' hour from dual当前时间减去7天的时间 select sys...

按照类型划分，锁可分为排他锁和共享锁。按照对象划分，锁可分为事务锁，DML锁，DDL锁，内存锁(Latch)。一.ORACLE中有关锁的动态性能视图主要有：V$LOCKThis view lists the locks currently held by the Oracl...

转载自:http://adian.itpub.net/post/22879/293659这两个概念很容易混淆。概念： OPEN_CURSOR，定义每个Session最大能够打开的游标数量。在init.ora文件中定义，可以通过select * from v$parameter where name = 'o...

转载自：http://database.e800.com.cn/articles/2008/37/1204834966442680122_1.htmlSESSION_CACHED_CURSORS,就是说的是一个session可以缓存多少个cursor，让后续相同的SQL语句不再打开游标,从而避免软解析的过程来...

一.说明：1.以下所说的当前日志指日志状态为CURRENT,ACTIVE,非当前日志指日志状态为INACTIVE2.不用考虑归档和非归档模式，2种模式下的Redo丢失情...

大鸟老师个人网站：http://www.qujon.com/小型机-RISC-简单指令集计算机PC服务器-CISC远程登陆-rloginctrl+d  //关闭一个终端cal 8 2009 //显示2009年8月日历表cal 8      //显...