Directions: Answer each of the following questions. Please ensure that your responses are at least 3 to 5 sentences in length.

1. What are two advantages of external storage when compared with internal memory?

2. In a sequential access file, how can data stored at a given position be accessed?

3. In a random access file, how can data stored at a given position be accessed?

4. What is a buffer?

5. When you consider the efficiency of an algorithm, why should you not pay much attention to the time required to operate on a block of data once it has been read into internal memory?

6. What is the main advantage of an external table implementation in which records are stored in search-key order?

7. What is the main disadvantage of an external table implementation in which records are stored in search-key order?

8. What is an index to a data file?

9. What is a key in an index file?

10. What is a pointer in an index file?

11. What are the three main advantages to maintaining an index to a data file?

12. What is meant by multiple indexing?

13. How do insertion and deletion operations for a sorted data file differ from those for an unsorted data file that has a sorted index?

14. What are the external table operations for which the hashing of an index file is an appropriate implementation?

15. What is the relationship between the number of records and the number of children that an internal node in a B-tree has?