1Z0-042填空题每日一练(2020.03.29)

单项选择题
You want to monitor and control the resource usage by sessions. You want to be warned automatically when more than 100 sessions are opened with your database. What action would you take to achieve this？（）
A.Use the Database Resource Manager.
B.Set the limits in the profiles used by users.
C.Modify the SESSIONS initialization parameter.
D.Set the warning threshold for the Current Logons Count metric.
单项选择题
The user SCOTT executes the following command successfully to increase the salary values in one of his sessions： SQL> UPDATE emp SET sal=sal*1.15 WHERE deptno=20; Before SCOTT ends the transaction， user HR who has the privileges on EMP table executes a query to fetch the salary details but finds the old salary values instead of the increased values. Why does HR still see the old data？（）
A.because of redo data from redo log file
B.because of data from database buffer cache
C.because of data from a temporary tablespace
D.because of undo data from the undo tablespace
多项选择题
Your boss at Certkiller .com wants you to clarify Oracle 10g. Which two steps are performed the first time any UPDATE statement is issued after the instance is started？（）
A.Creating the parse tree of the statement
B.Writing the modified data blocks to the data files
C.Writing the modified data to the archived redo log files
D.Updating the control file to indicate the most recent checkpoint
E.Updating the data file header to indicate the most recent checkpoint
F.Reading the blocks to database buffer cache if they are not already there
单项选择题
It is a holiday and no transactions are being performed on the database. You took a consistent backup of your database without using Recovery Manager （RMAN）. How would you make use of this consistent backup in RMAN？（）
A.cannot be used in RMAN
B.by starting up the database again
C.by using the CATALOG command of RMAN
D.by using the RECOVER CATALOG command in RMAN
E.by re-creating the target control file to rebuild the RMAN repository
单项选择题
You are connecting to an Oracle database server from a client by using the following connect string： SQL> CONNECT hr/hr@pdserver.us.oracle.com：1521/proddb Which naming method is being used in this case？（）
A.Local Naming
B.Easy Connect
C.External Naming
D.Directory Naming