You need to produce a report for mailing labels for all customers. The mailing label must have only the customer name and address. The CUSTOMERS table has these columns: Which SELECT statement accomplishes this task?（）

A、 SELECT* FROM customers;

B、 SELECT name, address FROM customers;

C、 SELECT id, name, address, phone FROM customers;

D、 SELECT cust_name, cust_address FROM customers;

E、 SELECT cust_id, cust_name, cust_address, cust_phone FROM customers;

When a database administrator chooses the dimensions for an MDC table, which two characteristics should beconsidered?（）

the query transaction rate 

numeric data versus character data  

extent size  

the cardinality of the candidate columns  

prefetch size 

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.

Which of the following datatypes are used in situations where you want an ordered set of data elements, where every element is the same datatype, and where you predefine the number of elements that appear in the set?（）

A、REF 

B、TABLE 

C、CLOB 

D、VARRAY

You are managing the Oracle database. Which of the following choices correctly identifies when Oracle reads the contents of the init.ora file?（）

A、When the instance is started 

B、When the database is mounted 

C、When the database is opened 

D、When the database is closed

Evaluate these two SQL statements: SELECT last_name, salary, hire_dateFROM EMPLOYEES ORDRE BY salary DESC; SELECT last_name, salary, hire_dateFROM EMPOLYEES ORDER BY 2 DESC; What is true about them? （）

A、The two statements produce identical results.

B、The second statement returns a syntax error.

C、There is no need to specify DESC because the results are sorted in descending order by default.

D、The two statements can be made to produce identical results by adding a column alias for the salary column in the second SQL statement.