多选题Examine the following command: CREATE TABLE (prod_id number(4), Prod_name varchar2 (20), Category_id number(30), Quantity_on_hand number (3) INVISIBLE); Which three statements are true about using an invisible column in the PRODUCTS table?（）AThe %ROWTY

A. CREATE TABLE EMP9$# AS (empid number(2));

B. CREATE TABLE EMP*123 AS (empid number(2));

C. CREATE TABLE PACKAGE AS (packid number(2));

D. CREATE TABLE 1EMP_TEST AS (empid number(2));

View the Exhibit for some of the current parameter settings. A user logs in to the HR schema and issues the following commands:SQL> CREATE TABLE emp(empno NUMBER(3),ename VARCHAR2(20),sal NUMBER(8,2));SQL> INSERT INTO emp(empno,ename) VALUES(1,‘JAMES‘);At this moment, a second user also logs in to the HR schema and issues the following command:SQL> ALTER TABLE emp MODIFY sal NUMBER(10,2);What happens in the above scenario?（）

A. The second user‘s session immediately produces the resource busy error.

B. The second user‘s command executes successfully.

C. The second user‘s session waits for a time period before producing the resource busy error.

D. A deadlock is created.

Examine the output of the query that you executed to list the objects in the recycle bin:You verified that no table named SALES_TAB exists in the schema. Then you executed the following command to purge the objects in the recycle bin:SQL> PURGE TABLE sales_tab;What would be the outcome of this command?（）

A. All three tables in the recycle bin are purged

B. Only the table with the oldest DROPSCN is purged

C. The command returns an error because multiple entries with the same name exist in the recycle bin

D. Only the table with the latest DROPSCN is purged

Examine the following command:CREATE TABLE (prod_id number(4),Prod_name varchar2 (20),Category_id number(30),Quantity_on_hand number (3) INVISIBLE);Which three statements are true about using an invisible column in the PRODUCTS table?（）

A. The %ROWTYPE attribute declarations in PL/SQL to access a row will not display the invisible column in the output.

B. The DESCRIBE commands in SQL *Plus will not display the invisible column in the output.

C. Referential integrity constraint cannot be set on the invisible column.

D. The invisible column cannot be made visible and can only be marked as unused.

E. A primary key constraint can be added on the invisible column.

You opened the encryption wallet and then issued the following command:Then you closed the wallet. Later, you issued the following command to create the EMPLOYEES table in the SECURESPACE tablespace and you use the NO SALT option for the EMPID column.What is the outcome?（）

A. It creates the table and encrypts the data in it.

B. It generates an error because the wallet is closed.

C. It creates the table but does not encrypt the data in it.

D. It generates an error because the NO SALT option cannot be used with the ENCRYPT option.

Examine the SQL statement that creates ORDERS table:CREATE TABLE orders (SER_NO NUMBER UNIQUE, ORDER_ID NUMBER, ORDER_DATE DATE NOT NULL, STATUS VARCHAR2(10) CHECK (status IN (‘CREDIT‘, ‘CASH‘)), PROD_ID NUMBER REFERENCES PRODUCTS(PRODUCT_ID), ORD_TOTAL NUMBER, PRIMARY KEY (order_id, order_date));For which columns would an index be automatically created when you execute the above SQL statement? （）

A. SER_NO

B. ORDER_ID

C. STATUS

D. PROD_ID

E. ORD_TOTAL

F. composite index on ORDER_ID and ORDER_DATE

A. CREATE TABLE orders ( order_id NUMBER (10), customer_id NUMBER (8), order_status VARCHAR2 (10), date_ordered DATE = SYSDATE);

B. CREATE TABLE orders ( order_id NUMBER (10), customer_id NUMBER (8), order_status VARCHAR2 (10), date_ordered DATE DEFAULT SYSDATE);

C. CREATE OR REPLACE TABLE orders ( order_id NUMBER (10), customer_id NUMBER (8), order_status VARCHAR2 (10), date_ordered DATE DEFAULT SYSDATE);

D. CREATE OR REPLACE TABLE orders ( order_id NUMBER (10), customer_id NUMBER (8), order_status NUMBER (10), date_ordered DATE = SYSDATE);

E. CREATE TABLE orders ( order_id NUMBER (10), customer_id NUMBER (8), order_status NUMBER (10), date_ordered DATE = SYSDATE);

F. CREATE TABLE orders ( order_id NUMBER (10), customer_id NUMBER (8), order_status NUMBER (10), date_ordered DATE DEFAULT SYSDATE);