Oracle9i New Features

　　原文链接：
　　http://download-west.Oracle.com/otndoc/oracle9i/901_doc/server.901/
　　a90117/whatsnew.htm
　　是编号为A90120-20文档的概括
　　前些天看到有人问9I的新功能，就随手翻译了一下有的地方不准确或者是错误的，大家多包涵不清楚的地方请参考文档，谢谢
　　
　　Oracle9i Release 1 (9.0.1) New Features
　　Oracle9i brings a major new release of the Oracle database server. It includ
　　es features to make the database more available. More online operations redUCe the need for offline maintenance. Management of the database requires less effort. Oracle9i can automatically create and manage the underlying operating system files required by the database. There is a theme of self management.
　　Oracle9i带来了一次Oracle数据库服务器的主要升级。它包括了可以使数据库更可靠，更多的在线操作替代了离线维护，治理数据库更有效的新特性。Oracle9i自动治理数据库需要的操作系统文件。这是自动治理的主题。
　　
　　Performance is enhanced. The Database Resource Manager has new options that allow for more granular control of resources. The performance level required of a resource consumer group can be better sustained. Partitioning enhancements allow tables and indexes to be better partitioned for performance. Security enhancements are an important part of this release. Applications have available more and finer grained methods of implementing security and auditing.
　　
　　性能得到增强。数据库资源治理器拥有新的选项，答应对资源进行更好的控制。一组资源消费所要求的性能水平可以得到持续满足。分区增强答应表和索引为性能更好的分区。安全增强是这次升级的重要部分。应用程序拥有更多更好的执行安全和审计的方法。
　　
　　The following are summaries of the new features of Oracle9i that are discussed in this book.
　　下面是Oracle9i新特性的总结。
　　
　　Online redefinition of tables
　　The new DBMS_REDEFINITION PL/SQL package provides a mechanism to redefine ta
　　bles online. When a table is redefined online, it is Accessible to DML durin
　　g much of the redefinition process. This provides a significant increase in
　　availability compared to traditional methods of redefining tables that require tables to be taken offline.
　　1. 在线重定义表
　　新的PL/SQL包DBMS_REDEFINITION提供了在线重定义表的机制。当表被在线重定义的时候，在重定义进程中的大多数时刻对DML是可用的。与传统的要求表先离线再重新定义的方法相比，显著地提高了可用性。
　　
　　ONLINE option for ANALYZE VALIDATE STRUCTURE statement
　　The ANALYZE statement can now perform validation while DML is ongoing within the object being analyzed.
　　2. ANALYZE VALIDATE STRUCTURE语句的ONLINE选项
　　ANALYZE语句现在可以在DML运行的时候提供确认，当目标正在分析的时候。

　　
　　Controlling Archive Log
　　Oracle now provides a time-based means of switching the current online redo log group. In a primary/standby configuration, where all noncurrent logs of the primary site are archived and shipped to the standby database, this effectively limits the number of redo records, as measured in time, that will not be applied in the standby database.
　　3. 控制归档日志
　　Oracle现在提供一种基于时间的方法用来切换目前的在线redo log组。在primary/standby配置中，既所有主站点非当前日志都被归档并传到standby数据库中，它有效地限制了重做记录的数量，从时间上考虑，它不使用在standby database上。
　　
　　Suspending a database
　　Oracle9i includes a database suspend/resume feature. The ALTER SYSTEM SUSPEND statement suspends a database by halting all input and output (I/O) to dat
　　afiles and control files. When the database is suspended all preexisting I/O
　　 operations are allowed to complete and any new database accesses are placed in a queued state. The ALTER SYSTEM RESUME statement resumes normal databas
　　e operation.
　　4. 挂起数据库
　　Oracle包括数据库挂起/恢复特性。ALTER SYSTEM SUSPEND语句通过暂停所有对数据文件和控制文件的输入输出（I/O）挂起数据库。当数据库被挂起时，所有先前存在的I/9操作被答应执行完毕并且任何新的请求被放在一个状态队列中。ALTER SYSTEM RESUME语句恢复正常的数据库操作。
　　
　　Quiescing a database
　　Oracle9i allows you to place the database into a quiesced state, where only DBA transactions, queries, or PL/SQL statements are allowed. This quiesced state allows you to perform administrative actions that cannot safely be done
　　 otherwise. The ALTER SYSTEM QUIESCE RESTRICTED statement places a database into a quiesced state
　　5. 禁用数据库
　　Oracle9i答应拥护将数据库置于一个禁用状态，只有DBA事务、查询或者PL/SQL语句可以执行。这个状态答应用户进行在其他情况下不能保证安全的治理工作。ALTER SYSTEM QUIESCE RESTRICTED语句将数据库设置为禁用状态。
　　
　　Resumable Space Allocation
　　Oracle provides a means for suspending, and later resuming, the execution of
　　 large database operations in the event of space allocation failures. This enables you to take corrective action, instead of the Oracle database server returning an error to the user. After the error condition is corrected, the suspended operation automatically resumes.
　　6. 空间分配可恢复
　　当大型数据库操作在空间分配阶段失败时，Oracle提供了一种先挂起，一段时间后恢复执行的机制。它可以答应纠正操作，代替数据库返回用户一个错误。当错误状态被纠正时，挂起的操作自动恢复。
　　
　　More archiving destinations
　　The maximum number of destinations to which you can archive the online redo
　　log, has been increased from 5 to 10.
　　7. 更多的归档目标文件
　　归档重做日志所用的目标文件的最大数量从5个增加到10个。
　　
　　Automatic segment- space management Locally managed tablespaces allow extents to be managed automatically by Oracle. Oracle9i allows free and used space within segments stored in locally managed tablespaces to also be managed automatically. Using the SEGMENT SPACE
　　 MANAGEMENT clause of CREATE TABLESPACE you specify AUTO or MANUAL to specify the type of segment space management Oracle will use.
　　8. 自动分段——空间治理
　　本地治理的表空间答应扩展段由Oracle自动治理。
Oracle9i也答应本地表空间段中的free和used空间自动治理。使用CREATE TABLESPACE的SEGMENT SPACE MANAGEMENT子句，通过设置AUTO或MANUAL确定Oracle用来治理段空间所使用的方法。
　　
　　Update of global indexes when partition maintenance is performed By default, many table maintenance operations on partitioned tables invalida
　　te (mark UNUSABLE) global indexes. You must then rebuild the entire global i
　　ndex or, if partitioned, all of its partitions. Oracle9i allows you to override this default behavior. When you specify the UPDATE GLOBAL INDEX clause in your ALTER TABLE statement for the maintenance operation, the global index is updated in conjunction with the base table operation.
　　9. 维护分区的时候更新全局索引
　　在缺省情况下，许多在分区表上进行的表维护操作使全局索引无效（标志为UNUSABLE）。用户必须重建全部的全局索引，或者在在分区的情况下，全部它的分区。Oracle9i答应用户使其无效。当用户在维护操作的ALTER TABLE语句中声明UPDATE GLOBAL INDEX子句时，全局索引和基表操作一起更新。
　　
　　Multiple block sizes
　　Oracle now supports multiple block sizes. It has a standard block size, as s
　　et by the DB_BLOCK_SIZE initialization parameter, and additionally up to 4 n
　　onstandard block sizes. Nonstandard block sizes are specified when creating
　　tablespaces. The standard block size is used for the SYSTEM tablespace and most other tablespaces. Multiple block size support allows for the transporting of tablespaces with unlike block sizes between databases.
　　10. 块大小多样化
　　Oracle现在支持多种块的尺寸。数据块具有一个标准的大小，建立表空间时在DB_BLOCK_SIZE初始化参数中设置。标准块大小用于SYSTEM表空间和大多数其他表空间。多样化的块大小答应数据库间具有不同块大小的表空间传输。
　　
　　Dynamic buffer cache
　　The size of the buffer cache subcomponent of the System Global Area is now dynamic. The DB_BLOCK_BUFFERS initialization parameter ha