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. none
B. DELETE, INSERT,SELECT
C. ALTER, DELETE, INSERT, SELECT
D. DELETE, INSERT, SELECT, UPDATE

A. SELECT ename, salary*12 ‘Annual Salary’   FROM employees;
B. SELECT ename, salary*12 “Annual Salary”   FROM employees;
C. SELECT ename, salary*12 AS Annual Salary   FROM employees;
D. SELECT ename, salary*12 AS INITCAP(“ANNUAL SALARY”)   FROM employees

A. Once created, a sequence belongs to a specific schema.
B. Once created, a sequence is linked to a specific table.
C. Once created, a sequence is automatically available to all users.
D. Only the DBA can control which sequence is used by a certain table.
E. Once created, a sequence is automatically used in all INSERT and UPDATE statements.