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11.Which two statements are true about Shared SQL Area and Private SQL Area? (Choose two.) A. Shared SQL Area will be allocated in the shared pool B. Shared SQL Area will be allocated when a session starts C. Shared SQL Area will be allocated in the large pool always D. The whole of Private SQL Area will be allocated in the Program Global Area (PGA) always E. Shared SQL Area and Private SQL Area will be allocated in the PGA or large pool F. The number of Private SQL Area allocations is dependent on the OPEN_CURSORS parameter Answer: AF
私有sql区存放的sql信息只被执行这个sql语句的会话所独有,其他会话不能共享这部分信息。
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12.Which three statements are correct about temporary tables? (Choose three.) A. Indexes and views can be created on temporary tables B. Both the data and structure of temporary tables can be exported C. Temporary tables are always created in a user‘s temporary tablespace D. The data inserted into a temporary table in a session is available to other sessions E. Data Manipulation Language (DML) locks are never acquired on the data of temporary tables Answer: ACE
Oracle临时表分为 会话级临时表 和 事务级临时表
临时表不需要DML锁.当一个会话结束(用户正常退出 用户不正常退出 ORACLE实例崩溃)或者一个事务结束的时候,Oracle对这个会话的表执行 TRUNCATE 语句清空临时表数据.但不会清空其它会话临时表中的数据.
你可以索引临时表和在临时表基础上建立视图.同样,建立在临时表上的索引也是临时的,也是只对当前会话或者事务有效
临时表通常是创建在用户的临时表空间中的,不同用户可以有自己的独立的临时表空间
临时表结构可被导出,但内容不可以被导出
不同的session不可以互相访问对方的临时表数据
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13.Which two kinds of failures make the Data Recovery Advisor (DRA) generate a manual checklist? (Choose two.) A. Failure when no standby database is configured B. Failure because a data file is renamed accidentally C. Failure that requires no archive logs to be applied for recovery D. Failure due to loss of connectivity-for example, an unplugged disk cable Answer: BD
DRA是oracle 11g的新特性
在遇到错误时会自动收集数据故障信息。此外,它还能预先检查故障。在此模式中,它可以在数据库进程发现损坏并发送错误消息之前检测和分析数据故障
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14.Which two statements correctly describe the relation between a data file and the logical database structures? (Choose two) A. An extent cannot spread across data files. B. A segment cannot spread across data files. C. A data file can belong to only one tablespace. D. A data file can have only one segment created in it. E. A data block can spread across multiple data files as it can consist of multiple operating system (OS) blocks. Answer: AC
数据块之上的逻辑数据库空间是数据扩展(extent)。数据扩展是为存储数据而分配的一组连续的数据块。
位于数据扩展之上的逻辑数据库存储结构是段(segment)。段由一组数据扩展 (extent)构成,这些数据扩展位于同一表空间(tablespace)中,用于存储各种逻辑数据结构。
一个段(segment)以及属于她的所有数据扩展(extent)必须包含在同一表空间(tablespace)中。但在一个表空间内,属于同一个段的数据扩展可以分布 在多个数据文件(datafile)上,即段可以跨文件存储。但是每个数据扩展只能包含于同一个数据文件中。
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15.Which two statements are true regarding a tablespace? (Choose two.) A. It can span multiple databases B. It can consist of multiple data files C. It can contain blocks of different files D. It can contains segments of different sizes E. It can contains a part of nonpartitioned segment Answer: BD
数据库空间的分配单位有数据块(Data Block),数据扩展(Extent),和段(Segment)
创建表空间可以加一个参数:BLOCKSIZE这个参数可以设定一个不标准的块的大小。如果要设置这个参数,必须设置db_block_size,至少一个db_nk_block_size,并且声明的integer的值必须等于db_nk_block_size.