IMP时数据库的IO性能监控,并提供IOPS的计算方法
[root@ntkdb oradata]# iostat -x 1 10 Linux 2.6.9-67.ELlargesmp (ntkdb) 07/15/2011 &nbs...
.10G RAC Data Gathering for Troubleshooting RAC and CRS issues
Help Did this article help solve your problem? Select Yes No Does Not Apply Would you recommend this document to others? Select Yes No Not Sure &...
Clustering Factor (Note:39836.1)
Clustering Factor (Note:39836.1)Clustering Factor is a measure of the orderedness of an index in comparisonto the table that it is based upon. It is used as an indicator for computing the estimated co...
Bug 5907779
今天早上数据库巡检发现cpu 100%,客户随后通知业务系统比较慢,输入如下命令:发现大量等待事件select sid,seq#,event from v$session_wait where wait_class <> 'Idle';SID &nbs...
/Dev/Async Traces After Upgrade To 10gR2 On HP-UX PA-RISC [ID 382674.1]
/Dev/Async Traces After Upgrade To 10gR2 On HP-UX PA-RISC [ID 382674.1] 修改时间 19-NOV-2010 类型 PROBLEM 状态 MODERATED In this DocumentSymptomsCauseSolutionReferences...
ORA-29558: JAccelerator (NCOMP) not installed报错分析
1 问题描述当给已创建好的数据库安装oracle10.2.0.4或oracle10.2.0.5补丁,运行catupgrd.sql脚本时会出现 ORA-29558: JAccelerator (NCOMP) not installed报错。select dbms_java.full_ncomp_enabled from dual*ERRO...
.EVENT: ADJUST_SCN
Calculating a Level from 600 errors: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ To get a LEVEL for ADJUST_SCN: &nbs...
CBO学习笔记系列4(转载)
full tablescan and CPU Cost这里我们看一下Oracle9i里面的CBO是如何使用system statistics的,重点看一下CBO如何计算CPU cost。我们前面介绍过oracle8i的CBO的一些缺点(参考:http://fusnow.itpub.net/post/681...
CBO学习笔记系列3(转载)
tablescan 之 不同block size的影响tablescan 之 不同block size的影响前面我们知道Oracle的CBO会根据操作系统的信息适当的调整db_file_multiblock_read_count的值,具体的测试结果如下 (CBO fundamentals原书上...
CBO学习笔记系列2(转载)
关于tablescan 之 自调整的db_file_multiblock_read_count今天打算超额完成任务。闲言碎语不要讲,来做个实验先!--这个实验是CBO fundamentals里面的。首先我的实验环境是Oracle 9.2.0.4,block size 8k,LMT,...
CBO学习笔记系列1(转载)
什么是COST?什么是COST?1. 关于CBO,我们都知道CBO是optimizer based on cost,我们很清楚optimizer是什么,based是什么,On是什么,但问题是:cost是什么?在Oracle8i里面,一条语句的cost基本上代表着Oracle...
undo损坏的数据库非常规的恢复
报错日志如下: cat lion_smon_7022.trc | more/u01/admin/lion/bdump/lion_smon_7022.trcOracle Database 10g Enterprise Edition Release 10.2.0.1.0 - ProductionWith the Partitioning, OLAP and D...
Oracle分区索引(转载)
分区索引分为本地(local index)索引和全局索引(global index)。其中本地索引又可以分为有前缀(prefix)的索引和无前缀(nonprefix)的索引。而全局索引目前只支持有前缀的索引。B树索引和位图索引都可以分区,但是HASH...