LIST Partitioning
This article is intended to introduce the enhancements to thenew partitioning method introduced in 9i, LIST Partitioning. [@more@]SCOPE & APPLICATION-------------------This article assumes the reader has an understanding of partitioning that was introduced in Oracle8 and Oracle8i.ORACLE9i LIST PARTITIONING--------------------------Oracle9i adds a new partitioning model called LIST partitioning to the set of partition methods already being supported in the Oracle RDBMS. List partitioning enab
原来是Flashback!
有同事问我”BIN$Mp6ghZLX+d/gQAEKcwNPQA==$0“这些是什么来的。我一查询如下:SQL> select owner,object_name,object_type from dba_objects where object_name like '%$Mp6ghZLX+d/gQAEKcwNPQA==$0%';OWNER------------------------------OBJECT_NAME--------------------------------------------------------------------------------OBJECT_TYPE-------------------BLACK_BERRY2BIN$Mp6ghZLX+d/gQAEKcwNPQA==$0TABLE是表,属于BLACK_BERRY2这个用户,但执行查询抛异常:SQL> select * from BIN$Mp6ghZLX+d/gQAEKcwNPQA==$0;sel
Oracle Database 11g Launch Webcast
Coming July 11, 2007 - Watch the Launch of Oracle Database 11g Live at 10 a.m. ETJoin us for a live Webcast of the launch of Oracle Database 11g. You'll learn how Oracle Database 11g will help you innovate faster through better business insight and improved information management. This is your opportunity to join leading industry experts from some of the most innovative companies and organizations of our time, including: James Burke, science historian, author, producer, and host of the BBC's acc
玩转Data Guard的switchover后切不回主库
今天在data guard(standby)的物理主库上做switchover后想切回来,结果费了半天。认识到到几个盲点:1、log_archive_dest_n(n>1)中的service指的是备用库的网络服务器名称;2、db_name指的是唯一的数据库名称;db_unique_name、service_names和instance_name均指的是某个节点的数据库名称;3、oradim的时候加上-intpwd不然会抛“ora-01031: insufficient privileges "的异常;4、监听文件listener.ora中listener跟sid_list_listener是配对出现的,可配多个监听。[@more@]
深圳楼市之怪现象
怪现象之一:“天天涨停” 6月,深圳楼价像深圳的天气一样火热。来自深圳有关部门的数据显示,深圳全市商品房成交均价为每平方米14223元,关内均价已过两万。深圳已经成为中国内地房价最高的城市。 怪现象之二:10人抢1套房很平常 截止6月,深圳房价5个月内暴涨50%,问及深圳目前最低价的楼盘在哪里?深圳人几乎都能回答:“关外”。即使最低价之地,“最便宜”的房屋,也并不是有钱就能买得到的,10个购房者争抢同一套房屋很平常。 怪现象之三:“满城尽带楼市VIP” 正因为10个购房者争抢同一套房屋已成为平常之事,开发商“创新性”
In Data Guard,choose switchover or failover?
SwitchoverAllows the primary database to switch roles with one of its standby databases.There is no data loss during a switchover. After a switchover, each database continues to participate in the Data Guard configuration with its new role.[@more@]FailoverTransitions a standby database to the primary role in response to a primary database failure. If the primary database was not operating in either maximum protection mode or maximum availability mode before the failure, some data loss may occur.
10g中单机上配置data guard的成功案例
在数据库的容灾方案中通常考虑data guard这一技术来实现应用系统的flexibility和usability。下面是我利用平时空闲时间在pc单机上配置oracle 10g的data guard物理备用数据库整个过程,供大家学习,也希望大家提出宝贵的建议给我。 [@more@]一、原理应该说物理备用数据库是主数据库的镜像,事务一致性副本。物理备用数据库通过应用主数据库的重做日志数据来跟主数据库保持同步。当主数据库发生事务变化时,oracle会将重做数据写入重做日志和归档日志中。后台进程MRP0定期将归档日志传送到物理备用数据库后物理备用数据库应用这些事务变化,从
About quota
告警日志中抛如下的异常:Mon Jun 25 13:36:06 2007ORA-1654: unable to extend index IMALLCSS.IDX_T_ACTIONLOG_USERID by 2048 in tablespace TS_IMALL Mon Jun 25 13:36:29 2007原因有二:[@more@]1、表空间TS_IMALL已满;2、用户IMALLCSS在表空间TS_IMALL上的quota不够。查询user_ts_quotas数据字典发现quota是unlimited的,如下:SQL> select * from user_ts_quotas;TABLESPACE_NAME BYTES MAX_BYTES BLOCKS MAX_BLOCKS------------------------------ ---------- ---------- ---------- ----------TS_IMALL 1507328 -1 368 -1说明
一次成功的优化案例
现网一后台报表程序如今运行越来越慢,目前竟然需22个小时才能搞定!程序是外包的兄弟开发的,涉及到的性能问题最终找到了我! [@more@]原来这个程序的运行机制其实很简单,从数据库中找到数据转换成.txt格式的文件输出,对应的数据库操作语句如下:SQL> select AcctId,2 SubsId,3 Acctstatus,4 to_char(OpenTime, 'YYYYMMDDHH24MISS'),5 1,6 QuotaOrder,7 to_char(ModifyTime, 'YYYYMMDDHH24MISS'),8 to_char(EXPIRTIME, 'YYYYMMDD'),9 nb,10 fb11 from (select a.AcctId,12 b.SubsId,13 a.Acctstatus,14 a.OpenTime,15 1,16 a.QuotaO
迁移数据库成功!
礼拜一参与了一项目的系统融合,迁移报表数据库成功。如下总结一下这一次的迁移过程。[@more@]两主机具有相同的平台,OS版本和patch。在目标主机上安装好oracle软件,这一步需保证具有相同的路径和文件目录名。将源主机上的oracle数据库shutdown后ftp所有的datafile,redo logfile,control file到目标主机上对应的目录下,然后将.bash_profile和.bashrc等环境变量文件也copy到目标主机上oracle用户的home目录下。紧接着就是重建密码文件;参照源主机oracle数据库上%ORACLE_HOME/network/admin下的transnames.ora,sql_net.ora和listener.or
oracle RFID
自从沃尔玛和美国国防部要求供应商逐步采用RFID技术后,RFID技术骤然升温。Oracle,IBM,Royal Philips Electronics,SAP,Intel,Sun,Microsoft等众多软件开发商纷纷投巨资在这个领域,希望取得技术领先优势。事实上,IDC预测在这项技术上的支出将从现在的US$91.5 million到2008年的US$1.3 billion。看看该领域小公司的股票表现就知道这项技术的火热啦。那么什么是RFID技术呢?[@more@]Oracle为数据仓库管理软件增加射频识别功能(zt) 近日,企业软件供应商甲骨文公司在美国总部宣布其最新版本的Oracle数据仓库管理软件(Oracle Wareho
Implementing Oracle9i Data Guard for Higher Availability
by Daniel T. LiuIntroduction One of the biggest responsibilities for a database administrator is provide high availability and reduce unplanned downtime for a database. However, this has become a major challenge as our database size increased so dramatically over the years and our critical business information system requires 24x7 uptime. In an unplanned downtime when a terabyte database was corrupted, it may take hours, even days to restore such a database. To minimize downtime and avoid data l
有关trigger的案例
一开发人员想实现利用表trigger往该表有条件地插入记录,即不满足条件的记录插入时通过trigger来拦截掉。找到了我帮忙是否可以实现,经深入分析后发觉根本无法实现这个功能。如下的试验可证明一切:[@more@]SQL> create table test_trigger 2 ( 3 name number(8) 4 );Table createdSQL> set serveroutput onSQL> CREATE OR REPLACE PROCEDURE proc_delete_test_trigger (p_name in varchar2) 2 IS 3 v_number number; 4 pragma autonomous_transaction; 5 BEGIN 6 7 begin 8 select count(*) into v_
非归档模式下数据文件被误删的解决方法
昨天停电一天,今早启动一数据库时抛“ORA-01251: Unknown File Header Version read for file number 42”,经咨询原来该文件被误删后将备份的文件copy回后结果导致文件头部信息不一致数据库无法open起来。现在急需解决的是要尽快启动数据库。[@more@][bocbi@portal3115 bdump]$ sqlplus /nologSQL*Plus: Release 10.2.0.1.0 - Production on Wed Jun 20 09:18:27 2007Copyright (c) 1982, 2005, Oracle. All rights reserved.SQL> conn / as sysdbaConnected.SQL> startup force mount;ORACLE instance started.Total System Glo
数据库无法shutdown immediate的案例
今日一哥们说数据库无法shutdown,一直挂着不动。我问是正常关闭么,答曰shutdown immediate。他问有无应急的办法让其关闭后重启,我说你就等等吧,immediate方式关闭的话很快能正常shutdown的。(许久后)我问down下来了么答曰没。不对劲呀![@more@]telnet上去一看发觉alert日志中有如下信息:Fri Jun 15 13:48:26 2007Shutting down instance: further logons disabledFri Jun 15 13:49:06 2007Shutting down instance (immediate)License high water mark = 990Fri Jun 15 13:54:14 2007Active call for process 16590 user 'oracle'
案例:在open状态下恢复未备份的数据文件
SQL> alter system switch logfile;系统已更改。SQL> archive log list数据库日志模式 存档模式自动存档 启用存档终点 H:archora10g最早的联机日志序列 31下一个存档日志序列 32当前日志序列 33[@more@]SQL> create tablespace test datafile 'H:oradataora10g est.dbf' size 10M;表空间已创建。SQL> create table test (name varchar2(128)) on test;create table test (name varchar2(128)) on test*第 1 行出现错误:ORA-00922: 选项缺失或无效SQL> create table test (name varchar2(128)) on tablespace test;create t
CKPT & SCN
Checkpoint是一个数据库事件,用来同步所有的datafile,controlfile和redo logfile。当发出ckpt时(回顾什么时候oracle会发出ckpt呢),ckpt会将检查点时刻的scn写入到控制文件和数据文件头部,同时会促使dbwr进程将data buffer中的所有的脏数据写入到数据文件中。而dbwr进程工作时又会促使lgwr写log buffer中的日志数据到redo logfile中。所以当发出检查点时CKPT,DBWR和LGWR同时工作,三种文件的scn完全一致,从而能保持完全同步。[@more@] 平时的commit操作只会促使LGWR写redo日志,DBWR只有在检查点时刻才会将脏
BULK COLLECT FAILS WITH ORA-04030
Recently We have a procedure that reads and distract data from a larger table O_APACHE_LOG(about 40 million rows per day) to many smaller one under some condition for ETL.[@more@]We are using the BULK COLLECT、FORALL and INSERT ALL statements to process data.When we have run the procedure,we capture two exceptions(ORA-04030: 在尝试分配 16408 字节 (koh-kghu call ,pmucalm coll) 时进程内存不足 & ORA-04030).we know that these exceptions occured because Operating system process private memory has
什么是RSS
RSS是站点用来和其他站点之间共享内容的一种简易方式(也叫聚合内容) [@more@]在门户网站大行其道,人们已经习惯通过搜索引擎来获取新闻资讯的今天,一种全新的资讯传播方式已经悄悄地来到我们身边,仔细观察一些网站,你可能注意到一些被标记为"XML"或"RSS"的橙色图标。 面对扑面而来的新闻,不用再花费大量的时间冲浪和从新闻网站下载,只要通过下载或购买一种小程序,这种技术被称为简易信息聚合(RSS:Really Simple Syndication)。RSS会收集和组织定制的新闻,按照你希望的格式、地点、时间和方式,直接传送到
Explain for the Statistics of Execution Plan
SQL> set autotrace traceonlySQL> select * from o_apache_log; 已选择1280000行。 [@more@] Execution Plan---------------------------------------------------------- 0 SELECT STATEMENT Optimizer=ALL_ROWS (Cost=8187 Card=1283425 Bytes=264385550) 1 0 TABLE ACCESS (FULL) OF 'O_APACHE_LOG' (TABLE) (Cost=8187 C ard=1283425 Bytes=264385550) Statistics---------------------------------------------------------- 1 recursive calls 0 db block gets