16、
16.Which two statements are true regarding Oracle Data Pump? (Choose two.) A. EXPDP and IMPDP are the client components of Oracle Data Pump B. DBMS_DATAPUMP PL/SQL packages can be used indedendently of the DATA Pump clients C. Oracle Data Pump export and import operations can be performed only by users with the SYSDBA privilege D. Oracle Data Pump imports can be done from the export files generated in the Original Export Release E. EXPDP and IMPDP use the procedures provided by DBMS_METADATA to execute export and import commands Answer: AB
数据泵是基于数据库服务端的，运行在数据库内部。
Oracle数据泵组成部分：命令行客户端（expdp和impdp）、数据泵API(DBMS_DATAPUMP)、元数据API(DBMS_METADATA).
Expdp和impdp调用数据泵API和元数据API共同完成数据的迁移。数据泵API执行表中数据的导入导出；元数据API完成元数据的装载和卸载。
17、
17.Identify the two situations in which the alert log file is updated with details. (Choose two.) A. Running a query on a table returns "ORA-600: Internal Error" B. Inserting a value in a table returns "ORA-01722: Invalid Number" C. Creating a table returns "ORA-00955: name is already used by an existing object' D. Inserting a value in a table returns "ORA-00001: unique constraint (SYS.PK_TECHP) violated." E. Rebuilding an index using ALTER INDEX ... REBUILD fails with an error "ORA-01578: ORACLE data block corrupted (file # 14, block @ 50)." Answer: AE
alert日志中记录：
Critical errors (incidents)
Administrative operations, such as starting up or shutting down the database, recovering the database, creating ordropping a tablespace, and others.
Errors during automatic refresh of a materialized view
Other database events
18、
18.Which two statements are true about alerts? (Choose two.) A. Clearing an alert sends the alert to the alert history B. Response actions cannot be specified with server-generated alerts C. The nonthreshold alerts appear in the DBA_OUTSTANDING_ALERTS view D. Server-generated alerts notify the problems that cannot be resolved automatically and require administrators to be notified Answer: AD
Oracle 10g通过DBA_OUTSTANDING_ALERTS视图记录了数据库活动警报信息，这些信息直到警告清除或复位才会从这个视图中消失
在Alerts 体系中，基于threshold 的alert 信息可以通过dba_outstanding_alerts视图查看，当这个警告被clear 后，信息会被转移，那么该警告信息可以通过dba_alert_history视图查看， 该视图里的历史数据也有有限的，其存放周期也受AWR的purge 策略影响。
19、
19.Examine the following steps performed on a database instance: 1. The DBA grants the CREATE TABLE system privilege to the SKD user with ADMIN OPTION 2. The SKD user creates a table 3. The SKD user grants the CREATE TABLE system privilege to the HR user 4. The HR user creates a table 5. The DBA revokes the CREATE TABLE system privilege from SKD Which statement is true after step 5 is performed? A. The table created by SKD is not accessible and SKD cannot create new tables B. The tables created by SKD and HR remain, but both cannot create new tables C. The table created by HR remains and HR still has the CREATE TABLE system privilege D. The table created by HR remains and HR can grant the CREATE TABLE system privilege to other users Answer: C
with admin option 用于系统权限授权，with grant option 用于对象授权。
给一个用户授予系统权限带上with admin option 时，此用户可把此系统权限授予其他用户或角色，但收回这个用户的系统权限时，这个用户已经授予其他用户或角色的此系统权限不会因传播无效
而with grant option用于对象授权时，被授予的用户也可把此对象权限授予其他用户或角色，不同的是但管理员收回用with grant option授权的用户对象权限时，权限会因传播而失效
20、
20.You execute this command to drop the ITEM table, which has the primary key referred in the ORDERS table: SQL> DROP TABLE scott.item CASCADE CONSTRAINTS PURGE; Which two statements are true about the effect of the command? (Choose two.) A. No flashback is possible to bring back the ITEM table. B. The ORDERS table is dropped along with the ITEM table. C. The dependent referential integrity constraints in the ORDERS table are disabled. D. The dependent referential integrity constraints in the ORDERS table are removed. E. The table definition of the ITEM table and associated indexes are placed in the recycle bin. Answer: AD
ALTER TABLE departments DROP CONSTRAINT pk_dept CASCADE;
The CASCADE clause causes Oracle Database to drop any foreign keys that reference the primary key.
