Observe the structure of the table employees: The table contains 8475 records. 
One of the employees wants to know the names of all employees of the company. For this, he fires the following query:
SELECT * FROM EMPLOYEES ORDER BY emp_fname;
Since the operation performed on executing the query cannot fit into memory, it requires disk space to complete the operation. Which of the following types of segments will Oracle allocate to complete the operation and to provide the required result?
A. Rollback segment
B. Temporary segment
C. Data segment
D. Index segment
原文：http://www.cnblogs.com/Babylon/p/7844379.html