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

A

the query transaction rate 

B

numeric data versus character data  

C

extent size  

D

the cardinality of the candidate columns  

E

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.

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.

 You are creating tablespaces in Oracle. Which of the following keywords or clauses permits the datafiles of a database to grow automatically in order to accommodate data growth?（）

A、DEFAULT STORAGE 

B、EXTENT MANAGEMENT 

C、AUTOEXTEND 

D、DATAFILE

软件商标权的保护对象是指（）。

A、商业软件

B、软件商标

C、软件注册商标

D、已使用的软件商标

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