1Z0-042单项选择题每日一练(2019.01.23)

单项选择题
You executed the following command to start the database： SQL> STARTUP ORACLE instance started. Total System Global Area 281018368 bytes Fixed Size 789000 bytes Variable Size 229635576 bytes Database Buffers 50331648 bytes Redo Buffers 262144 bytesORA-00205： error in identifying controlfile， check alert log for more info Which view would you query at this stage to investigate this missing control file？（）
A.V$INSTANCE
B.V$CONTROLFILE
C.DBA_CONTROL_FILES
D.V$DATABASE_PROPERTIES
E.V$CONTROLFILE_RECORD_SECTION
单项选择题
You work as a database administrator for Certkiller .com. You are using Recovery Manager （RMAN） for backup and recovery of your database. You executed the delete command in RMAN to delete a backup of atablespace. Which statement is true in this scenario？（）
A.A
B.B
C.C
D.D
E.E
单项选择题
Your boss at Certkiller .com wants you to clarify Oracle 10g. Which condition in your database forces you to perform only consistent backups？（）
A.The database is in mount state.
B.One of the tablespaces is offline.
C.One of the tablespaces is read only.
D.The database operates in ARCHIEVELOG mode.
E.The database operates in NOARCHIEVELOG mode.
单项选择题
You work in a data warehouse environment that involves the execution of complex queries. The current content of the SQL cache holds the ideal workload for analysis. You want to analyze only few most resource-intensive statements. What would be your suggestion to receive recommendations on the efficient use of indexes and materialized views to improve query performance？（）
A.Run the SQL Access Advisor.
B.Run the SQL Tuning Advisor （STA）.
C.Run the Automatic Workload Repository （AWR） report.
D.Run the Automatic Database Diagnostic Monitor （ADDM）.
单项选择题
You are working on an online transaction processing （OLTP） system. You notice that a PL/SQL procedure got executed twice at 2） 00 p.m. This has incorrectly updated the EMP_SAL table. How would you revert the table to its state at 2） 00 p.m.？（）
A.Perform point-in-time recovery to 2： 00 p.m.
B.Use Flashback Table feature to revert the changes.
C.Restore the entire database from the recent backup and open it.
D.Issue the rollback statement with system change number （SCN）.