The application workload on your database is same between 10 a.m. and 11 a.m. on weekdays. Suddenly you observe poor performance between 10 a.m. and 11 a.m. in the middle of the week. How would you identify the changes in configuration settings， workload profile，and statistics to diagnose the possible causes of the performance degradation？（）

单项选择题Your database is functional with peak load for one hour. You want to preserve the performance statistics collected during this period so that they can be used for comparison while analyzing the performance of the database in the future.  What action would you take to achieve this task？（）

A.Set the STATISTICS_LEVEL initialization parameter to ALL.
B.Create a baseline on a pair of snapshots that have the statistics of the peak­load period in the database.
C.Decrease the snapshot interval in the AWR to collect more number of snapshots during the peak­load period.
D.Set the snapshot retention period in the Automatic Workload Repository （AWR） to zero to avoid theautomatic purging of the snapshots.

单项选择题Inyourdatabase，theSTATISTICS_LEVELinitializationparameterissettoBASIC.Whatistheimpactofthissetting？（）

A.The optimizer statistics are collected automatically.
B.Only the timed operating system （OS） statistics and plan execution statistics are collected.
C.The Oracle server dynamically generates the necessary statistics on tables as part of query optimization.
D.The snapshots for the Automatic Workload Repository （AWR） are not generated automatically. 
E.Snapshots cannot be collected manually by using DBMS_WORKLOAD_REPOSITORY PACKAGE.

单项选择题InwhichsituationwouldyouusetheOracleSharedServerconfiguration？（）

A.when performing export and import using Oracle Data Pump
B.when performing backup and recovery operations using Oracle Recovery Manager
C.when performing batch processing and bulk loading operation in a data warehouse environment 
D.in an online transaction processing （OLTP） system where large number of client sessions are idle most of the time

单项选择题Your database is open and users are connected using the LISTENER listener. The new DBA of the system stops the listener by using the following command： LSNRCTL> STOP  What would happen to the sessions that are presently connected to the database instance？（）

A.The sessions are able to perform only queries.
B.The sessions are not affected and continue to function normally.
C.The active transactions are rolled back and the sessions get terminated.
D.The sessions are not allowed to perform any operations till the listener is started.

单项选择题You have been recently hired as a database administrator. Your senior manager asks you to study the production database server and submit a report on the settings done by the previous DBA.  While observing the server settings， you find that the following parameter has been set in the parameter file of the database：  REMOTE_OS_AUTHENT = TRUE  What could have been the reason to set this parameter as TRUE？（）

A.to enable operating system authentication for a remote client
B.to restrict the scope of administration to identical operating systems
C.to allow the start up and shut down of the database from a remote client
D.to enable the administration of the operating system from a remote client
E.to disable the administration of the operating system from a remote client