ou are in the middle of a transaction updating a very important table. The machine on which adatabase was running reboots because of power outage. This caused a database instance failure. 
Which statement is true in this situation（）

单项选择题Given below is a list of scenarios：  1）A user terminates his session abnormally.  2）The connection between the server and the client application terminates because of a network failure.  3）A schema is accidentally dropped.  4）The tablespace is accidentally dropped from the database.  5）The hard disk gets corrupted and the data files in the disk are lost.  6）The database instance abnormally shuts down because of power failure.  Which scenarios require DBA intervention to perform recovery（）

A.4 and 5
B.1，3，and 6
C.4，5，and 6
D.3，4，and 5
E.1，2，and 6

多项选择题InwhichofthescenarioswilltheDBAperformrecovery（）

A.The alert log file is corrupted.
B.A tablespace is accidentally dropped.
C.One of the redo log members is corrupted.
D.A database user terminates the session abnormally.
E.The hard disk on which the data file is stored is corrupted.

单项选择题View the Exhibit and examine the parameters. User A executes the following command to update the TRANS table： SQL> UPDATE B.trans SET tr_amt=tr_amt+500 WHERE c_code=’C005’；  Before user A issues a COMMIT or ROLLBACK command， user B executes the following command onthe TRANS table：  SQL> ALTER TABLE trans MODIFY （tr_type VARCHAR2（3））；  What would happen in this scenario（）

A.The ALTER TABLE command modifies the column successfully.
B.The DDL operation gets higher priority and transaction for user a is rolled back.
C.The ALTER TABLE command waits indefinitely until user a ends the transaction.
D.The ALTER TABLE command fails after waiting for 60 seconds due to the resource being busy.

单项选择题Automatic Shared Memory Management is disabled for your database instance. You realize that thereare cases of SQL statements performing poorly because of repeated parsing activity， resulting indegradation of performance.  What would be your next step to improve performance？ （）

A.Run the SQL Access Advisor.
B.Run the Memory Advisor for the sga.
C.Run the Memory Advisor for the pga.
D.Run the Memory Advisor for the shared pool.
E.Run the Memory Advisor for the buffer cache.

单项选择题View Exhibit1 and Exhibit2 to examine the current memory allocation and parameter settings，respectively. Why are advisors not available for the shared pool and the buffer cache()

A.because the DB_CACHE_ADVICE parameter is set to OFF
B.because Automatic Memory Management （AMM） is disabled for the database instance
C.because Automatic Shared Memory Management （ASMM） is enabled for the database instance
D.because the values for the DB_CACHE_SIZE and SHARED_POOL_SIZE parameters were not setinitially