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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允许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。这个状态允许用户进行在其他情况下不能保证安全的管理工作。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。它可以允许纠正操作，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——空间管理 本地管理的表空间允许扩展段由Oracle自动管理。Oracle9i也允许本地表空间段中的free和used空间自动管理。使用CREATE TABLESPACE的SEGMENT SPACE MANAGEMENT子句，通过设置AUTO或MANUAL确定Oracle用来管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允许用户使其无效。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。多样化的块大小允许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 (责任编辑：编程世界) |