Chapter 9  Searching: Instructor's CD questions

1. Which is generally more expensive?
a) A successful search.
*b) An unsuccessful search.

2. When properly implemented, which search method is generally the
most efficient for exact-match queries?
a) Sequential search.
b) Binary search.
c) Dictionary search.
d) Search in self-organizing lists
*e) Hashing

3. Self-organizing lists attempt to keep the list sorted by:
a) value
*b) frequency of record access
c) size of record

4. The 80/20 rule indicates that:
a) 80% of searches in typical databases are successful and 20% are not.
*b) 80% of the searches in typical databases are to 20% of the records.
c) 80% of records in typical databases are of value, 20% are not.

5. Which of the following is often implemented using a self-organizing list?
*a) Buffer pool.
b) Linked list.
c) Priority queue.

6. A hash function must:
*a) Return a valid position within the hash table.
b) Give equal probability for selecting an slot in the hash table.
c) Return an empty slot in the hash table.

7. A good hash function will:
a) Use the high-order bits of the key value.
b) Use the middle bits of the key value.
c) Use the low-order bits of the key value.
*d) Make use of all bits in the key value.

8. A collision resolution technique that places all records directly
into the hash table is called:
a) Open hashing.
b) Separate chaining.
*c) Closed hashing.
d) Probe function.

9. Hashing is most appropriate for:
a) In-memory applications.
b) Disk-based applications.
*c) Either in-memory or disk-based applications.

10. Hashing is most appropriate for:
*a) Range queries.
b) Exact-match queries.
c) Minimum/maximium value queries.

11. In hashing, the operation that will likely require more record
accesses is:
*a) insert
b) delete