CSIC 660 Assignment #4 Complete Solution

Question: #1563

Nova Southeastern University
Graduate School of Computer and Information Sciences
CSIC 660 Database Management Systems
Assignment #4

A. Please select the most appropriate solution in each of multiple choice questions in the
following: (60 points) (Please circle the most appropriate one for your answer carefully!)
1. A database system consists of
a. databases. b. database management systems.
c. both a. and b. d. neither a. nor b.
2. A database management system is
a. a piece of software. b. a piece of hardware.
c. a piece of both software and hardware. d. neither a piece of software nor hardware.
3. A database is
a. a collection of data. b. a set of data tables.
c. either a. or b. is correct d. neither a. nor b. is correct
4. A data model consists of
a. schema. b. set of operations.
c. set of constraints. d. all of a., b., and c.
5. A database language consists of
a. data definition language. b. data manipulation language.
c. both a. and b. d. neither a. nor b.
6. The data definition language defines
a. the schema or structure of a database. b. the set of operations in a database.
c. both a. and b. d. neither a. nor b.
7. The data manipulation language describes
a. the schema or structure of a database. b. the set of operations in a database.
c. both a. and b. d. neither a. nor b.
8. The purpose of three level database architecture is to support
a. data dependence. b. data independence.
c. both a. and b. d. neither a. nor b.
9. The Entity-Relationship data model is
a. DBMS dependent. b. DBMS independent.
c. both a. and b. d. neither a. nor b.
10. The relational data model is
a. external data model. b. physical data model.
c. logical data model. d. internal data model.
11. A key in a database table
a. is a minimal set of attributes. b. uniquely identifies a tuple in the table.
c. both a. and b. d. neither a. nor b.
12. A key in a database table is
a. a proper subset of a candidate key. b. a proper superset of a candidate key.
c. a minimal superkey. d. none of a., b., and c. are correct.
13. A foreign key can be
a. an attribute that is a primary key of another table.
b. an attribute that is a primary key of the same table.
c. either a. or b.
d. neither a. nor b.
14. A referential integrity constraint states
a. a foreign key attribute value must refer to an existing primary key value.
b. a foreign key attribute value can be NULL.
c. both a. and b.
d. neither a. nor b.
15. The lowest normal form the relational database model supports is
a. the first normal form. b. the second normal form.
c. the third normal form. d. Boyce-Codd normal form.
16. ____________ is an index specified on the ordering key field of an ordered file of records.
a.) Primary index b.) Clustering index
c.) Secondary index d.) None of the above
17. ____________ is an index specified on the nonkey ordering field of an ordered file of records.
a.) Primary index b.) Secondary
c.) Clustering index d.) None of the above
18. ____________ is an index specified on the key or nonkey nonordering field of a file of records.
a.) Primary index b.) Secondary
c.) Clustering index d.) None of the above
19. In __________________, the number of (first-level) index entries is equal to the number of
data blocks in data file.
a.) Primary index b.) Secondary
c.) Clustering index d.) None of the above
20. In __________________, the number of (first-level) index entries is equal to the number of
distinct index values in data file.
a.) Primary index b.) Secondary
c.) Clustering index d.) None of the above
21. In __________________, the number of (first-level) index entries is equal to the number of
records in data file.
a.) Primary index b.) Secondary
c.) Clustering index d.) None of the above
22. _____________________ is/are the dense index(es).
a.) Primary index b.) Secondary
c.) Clustering index d.) Both b.) and c.)
23. _____________________ is/are the nondense index(es).
a.) Primary index b.) Secondary
c.) Clustering index d.) Both a.) and c.)
24. _____________________ use(s) block anchoring on the data file.
a.) Primary index b.) Secondary
c.) Clustering index d.) Both a.) and c.)
25. ______________________ uses the less number of blocks to hold necessary index entries
(Assume the number of records is very big).
a.) Primary index b.) Clustering index
c.) Secondary index d.) Either a. or b.
26. ______________________ has the least number of block accesses to search and retrieve a
record (Assume the number of records is very big).
a.) Primary index b.) Secondary index
c.) Clustering index d.) B-tree and B+-tree
27. ______________________ guarantee(s) the access structure is always balanced when a lot of
updates such as insertions and deletions of file records occur .
a.) M-Way Search tree b.) Dynamic hashing
c.) Multilevel index d.) B-tree and B+-tree
28. ________________ guarantee(s) that the number of index block accesses is equal to the level of
the index structures.
a.) Multilevel index b.) M-Way Search tree
c.) Hashing d.) B-tree and B+-tree
29. The number of multi-level index depends on
a.) The number of records b.) The size of index block
c.) The size of index entries d.) All of a., b., and c.
30. Which of the following is correct?
a.) Multi-level index is designed to reduce the search cost of index part with a reduction ratio of
logarithm function.
b.) Multi-level index is guaranteed to have the search cost proportional to the number of levels in
multi-level index.
c.) Both a. and b. are correct.
d.) Neither a. or b. is correct.
B. Please indicate what the highest normal form is for the following given relational schemas:
(40 points)
a. R(A, B, C, D) key: AB FD: A  C, B  D
b. R(A, B, C, D) key: AB FD: AB  C, C  D
c. R(A, B, C, D) key: AB FD: AB  C, AB  D, D  B
d. R(A, B, C, D) key: AB FD: AB  C, AB  D
Please note FD is a set of functional dependencies.