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Required parameter:dispatchersoptional parameters:shared_servers、max_shared_servers、circuits、shared_server_sessions这5个参数均是动态参数，可以动态修改。[@more@]DISPATCHERS = “(PROTOCOL=TCP)(DISPATCHERS=2)(PROTOCOL=IPC)(DISPATCHERS=1)”dispatchers的属性值中还可以有如下参数service：dispatcher注册的net service name，没有给出采用services_name中的；listener：监听动态注册，非默认端口1521或没有在local_listener中给出时需使用；sessions：每个dispacther的会话数connections：每个dispacther连接数通过查询v

For a listener to forward client connections to an instance, the listener must know the name of the instance and where the instance’s ORACLE_HOME is located. The listener can find this information in two ways:1、Dynamic service registration: Oracle8i, Oracle9i, and Oracle Database 10g instances automatically register with the default listener on database startup. No additional listener configuration is required for the default listener.2、Static service registration: The earlier releases of the

下面列举十条流传甚广的传言，你可以测测自己在这场大灾中的智商得分。 　　如果你看到这些传言，第一反应是思索一秒钟，问问自己这可能吗？冷静的等待进一步证实的消息，或者是上网去搜索相关的知识与资料，那么恭喜你，加十分。如果你的反应是不假思索的相信、愤怒、甚至破口大骂，那么此条测试你的得分为零分。如果更进一步，你一看到就激动万分的立即转发到各个群、各个邮箱、各个论坛，迫不及待的告诉自己认识的其他朋友，那么此题你得负十分。[@more@]　　有人可能会说，谣言一开始被传的时候，都是言之凿凿，有的还有附图或视频，一

汶川7.8级地震牵挂了亿亿万万人民的心！昨晚看CCTV，白岩松朗诵了一首王先生写的诗，相当的感人。《生死不离》生死不离，你的梦落在那里 想着生活继续天空失去美丽，你却等待明天站起无论你在哪里，我都要找到你血脉能创造奇迹你的呼喊就刻在我的血液里 生死不离，我数秒等你消息相信生命不息我看不到你，你却牵挂在我心里无论你在哪里，我都要找到你血脉能创造奇迹搭起双手筑成你回家的路基 生死不离，全世界都被沉寂痛苦也不哭泣爱是你的传奇，彩虹在风雨后升起无论你在哪里，我都要找到你血脉能创造奇迹你一丝希望是我全部的动力[@more

1、概要资源文件profile的设定；2、表空间配额quota的设置；3、级联授权机制（系统权限中的with admin option和对象权限中的with grant option）；4、特殊用户public，可理解为所有数据库用户的集合；5、两个特殊的系统权限SYSDBA和SYSOPER[@more@]

在Oracle数据库中有三种方式的鉴权口令认证方式，分别是：1、数据库方式；2、密码文件方式；3、操作系统方式。其中数据库方式的认证只有在数据库run状态下普通用户连接上数据库时通过存储在字典表中的用户口令来进行鉴权认证。比如用户test的密码是testP，这该密码可通过查询dba_users中的password来获取，加密的；对于非普通用户，也即具有SYSDBA或SYSOPER的用户登陆数据库可以通过密码文件或操作系统层面的鉴权来访问数据库。有如下的几个参数来决定是采用那个途径来获取鉴权方式。首先初始化参数文件中的参数REMOTE_LOGIN_PASSWORDFILE

V$ASM_CLIENT contains one row for every database instance using a disk group managed by the ASM instance. In a database instance, it has one row for each disk group.V$ASM_DISKGROUP contains one row for every disk group discovered by the ASM instance. In a database instance, V$ASM_DISKGROUP has a row for all disk groups mounted or dismounted.V$ASM_TEMPLATE contains one row for every template present in every disk group mounted by the ASM instance. In a database instance, it has rows for all templ

驱动包classes12.jar用于JDK 1.2和JDK 1.3，而ojdbc14.jar用于JDK 1.4及以上，所以尽量不要使用classes12.jar；针对不同的数据库版本选择相应版本的驱动包；将驱动包置入应用启动的classpath中(jboss的lib或者项目lib)可通过如下链接下载到对应的驱动包：http://www.oracle.com/technology/software/tech/java/sqlj_jdbc/htdocs/jdbc9201.html[@more@]

When you have a performance problem, what comes to mind first to reduce the response time? Obviously, you want to eliminate (or reduce) the root cause of the factor that adds to the time. How do you know where the time was spent--not waiting, but actually doing the work?[@more@]Oracle Database 10g introduces time models for identifying the time spent in various places. The overall system time spent is recorded in the view V$SYS_TIME_MODEL. Here is the query and its output：SQL> select * from

If the tables are not really dropped in this process--therefore not releasing the tablespace--what happens when the dropped objects take up all of that space?[@more@]The answer is simple: that situation does not even arise. When a tablespace is completely filled up with recycle bin data such that the datafiles have to extend to make room for more data, the tablespace is said to be under "space pressure." In that scenario, objects are automatically purged from the recycle bin in a first

Ever had a need to export only certain procedures from one user to be recreated in a different database or user? Unlike the traditional export utility,Data Pump allows you to export only a particular type of object. For instance, the following command lets you export only procedures, and nothing else--no tables, views, or even functions:expdp ananda/iclaim directory=DPDATA1 dumpfile=expprocs.dmp include=PROCEDURE[@more@]To export only a few specific objects--say, function FUNC1 and procedure PRO

1. Oracle Database 10g: Program with PL/SQL 2. Oracle Database 10g: Program with PL/SQL LWC 3. Oracle Enterprise Manager 10g Grid Control 4. Oracle Database 10g: SQL Tuning Workshop 5. Oracle Database 10g: Real Application Clusters 6. Oracle Database 10g: Data Guard Administration 7. Oracle Database 10g: Implement Streams 8. Oracle Database 10g: Advanced PL/SQL 9. Oracle Database 10g: Security 10. Migrate from SQL Server to Oracle Database 10g 11. Migrate from Sybase to Oracle Database 10g 12. O

应用程序抛了如下的异常：SQL> exec PR_COMPARE_FREEZEBALANCE_TEMP();begin PR_COMPARE_FREEZEBALANCE_TEMP(); end;ORA-01555: snapshot too old: rollback segment number 10 with name "_SYSSMU10$" too smallORA-06512: at "MOCSACCT.PR_COMPARE_FREEZEBALANCE_TEMP", line 16ORA-06512: at line 1在告警日志中发现如下的异常：[@more@]Wed Mar 12 20:09:22 2008ORA-01555 caused by SQL statement below (Query Duration=11325 sec, SCN: 0x000d.7a79d7d1):Wed Mar 12 20:09:22 2008SELECT B.ACCTID,NVL(B.FR

index unique scanindex range scanindex full scanindex fast full scanindex skip scanIndex unique scan~~~~~~~~~~~~~~~~~Method for looking up a single key value via a unique index.always returns a single valueYou must supply AT LEAST the leading column of the index to access data viathe index, However this may return > 1 row as the uniqueness will not beguaranteed.[@more@]example explain plan:SQL> explain plan forselect empno,ename from emp where empno=10;Query Plan---------------------------

最近一OLTP生产数据库采用物化视图后性能明显提升，越来越发觉物化视图是把利器了。今天继续尝试物化视图中的一些奇妙的地方。如下是案例的整个过程，供大家学习和引用！[@more@]1、先创建两张表test_1和test_2：SQL> conn shiyihai/shiyihai@db80Connected to Oracle9i Enterprise Edition Release 9.2.0.6.0 Connected as shiyihaiSQL> SQL> drop table test_1;Table droppedSQL> create table test_12 (3 test_date date,4 id number(8),5 address varchar2(24)6 );Table createdSQL> drop table test_2;Table droppedS

Server Configuration [ ] Create the database [ ] Determine and set sizing parameters for database structures [ ] Create and manage temporary, permanent, and undo tablespaces [ ] Stripe data files across multiple physical devices and locations [ ] Configure the database environment to support optimal data access performance [ ] Create and manage database configuration files [ ] Create and manage bigfile tablespaces [ ] Create and manage multiple network configuration files [ ] Create and configur

All the files needed to recover a database from a media failure or a logical error are contained in the flash recovery area. The files that can reside in the flash recovery area are as follows:Control filesA copy of the control file is created in the flash recovery area when the database is created. This copy of the control file can be used as one of the mirrored copies of the control file to ensure that at least one copy of the control file is available after a media failure.[@more@]Archived lo

There are several new other background processes in 10g/11g,as following：MMON performs various manageability-related background tasks, for example:*Issuing alerts whenever a given metrics violates its threshold value*Taking snapshots by spawning additional process (MMON slaves)*Capturing statistics value for SQL objects which have been recently modifiedMMNL stands for manageability monitor light which is responsible to flush the information to the repository and performs frequent and light-weig

今天一部门开发人员通过公司BQQ问我是否可以在脚本中获取到update语句执行后的更新行数，并想知道返回值。我做了一个小试验，如下的内容很适合他借以利用。这个案例的关键字有sql%notfound、sql%rowcount和return，适合在脚本或应用中加以使用。[@more@]SQL> create table test_return 2 ( 3 name varchar2(24) 4 );Table createdSQL> insert into test_return values('111');1 row insertedSQL> insert into test_return values('222');1 row insertedSQL> commit;Commit completeSQL> SQL> set serveroutput o

The ORACLE_DATAPUMP access driver unloads data from an Oracle database to a flat file (DPAPI format) using the external table method. The external table must be created using the CREATE TABLE ... AS SELECT ... (CTAS) method. You can specify the PARALLEL clause when creatingthe table; ORACLE_DATAPUMP access driver unloads data into multiple flat files at the same time. One parallel execution server will write to only one file at a time. Unloading data in the context of external table means creati