ch10i.txt

（英文原版）数据结构与算法分析（C++版）单选试题与答案

Chapter 10  Indexing: Instructor's CD questions

1. An entry-sequenced file stores records sorted by:
a) Primary key value.
b) Secondary key value.
*c) Order of arrival.
d) Frequency of access.

2. Indexing is:
a) Random access to an array.
*b) The process of associating a key with the location of a
corresponding data record.
c) Using a hash table.

3. The primary key is:
*a) A unique identifier for a record.
b) The main search key used by users of the database.
c) The first key in the index.

4. Linear indexing is good for all EXCEPT:
a) Range queries.
b) Exact match queries.
*c) Insertion/Deletion.
d) In-memory applications.
e) Disk-based applications.

5. An inverted list provides access to a data record from its:
a) Primary key.
*b) Secondary key.
c) Search key.

6. ISAM degrades over time because:
a) Delete operations empty out some cylinders.
*b) Insert operations cause some cylinders to overflow.
c) Searches disrupt the data structure.

7. Tree indexing methods are meant to overcome what deficiency in
hashing?
*a) Inability to handle range queries.
b) Inability to handle updates.
c) Inability to handle large data sets.

8. Tree indexing methods are meant to overcome what deficiency in
linear indexing?
a) Inability to handle range queries.
*b) Inability to handle updates.
c) Inability to handle large data sets.

9. Tree indexing methods are meant to overcome what deficiency in
in-memory data structures such as the BST?
a) Inability to handle range queries.
b) Inability to handle updates.
*c) Inability to handle large data sets.

10. A 2-3 tree is a specific variant of a:
a) Splay tree.
*b) B-tree.
c) BST.
d) Trie.

11. The most important advantage of a 2-3 tree over a BST is that:
a) The 2-3 tree has fewer nodes.
b) The 2-3 tree has a higher branching factor.
*c) The 2-3 tree is height balanced.

12. The B-tree:
a) Extends the leaf nodes downward.
*b) Extends the root node upwards.

13. The primary difference between a B-tree and a B+-tree is:
*a) The B+-tree store records only at the leaf nodes.
b) The B+-tree has a higher branching factor.
c) The B+-tree is hight balanced.
d) The B+-tree is smaller.

14. The primary difference between a B+-tree and a B*-tree is:
a) The B+-tree store records only at the leaf nodes.
b) The B+-tree has a higher branching factor.
c) The B+-tree is hight balanced.
*d) The B+-tree is smaller.

15. In real-life applications, the B+-tree will typically have about
how many levels?
a) log n (base 2) for n > 1000.
b) 16
c) 8
*d) 4
e) 2
f) 1