LOGICAL DATABASE DESIGN - Fundamentals of Database Management Systems - page 194

to convert it to a well structured relational database structure. The other technique
is the data normalization technique. Furthermore, the data normalization technique
can be used to check the results of the E-R diagram conversion for errors.
SQL is both a data definition language and a data manipulation language.
Included in the basic data definition commands are CREATE TABLE, DROP
TABLE, CREATE VIEW, AND DROP VIEW. Included in the basic data

manipulation commands are UPDATE, INSERT, and DELETE.

KEY TERMS

CREATE TABLE
CREATE VIEW
Data normalization
Data structures
Database design
DELETE

DROP TABLE
DROP VIEW
Entity-relationship diagram conver-
sion
First normal form
INSERT

Logical database design
Second normal form
Third normal form
UPDATE

QUESTIONS

1. What is logical database design?
2. What is physical database design and how does it
relate to logical database design?
3. In general terms, describe the main logical database
design

9. What characterizes tables in first normal form? Why
is such data problematic?
10. What is a partial functional dependency? What does
the term ''fully functionally dependent'' mean?
11. What is the rule for converting tables in first normal
form to tables in second normal form?
12. What is the definition of data in second normal
form?
13. What is a transitive dependency?
14. What is the rule for converting tables in second
normal form to tables in third normal form?
15. What is the definition of data in third normal form?
16. What are the characteristics of data in third normal
form?
17. How can data normalization be used to check the
results of the E-R diagram-to-relational database
conversion process?
18. What SQL command do you use to produce a new
table structure? What SQL command do you use to
discard a table?
19. What is a view? What SQL commands do you use
to produce a new view and to discard one that is no
longer needed?
20. What are the SQL data manipulation commands and
what are their functions?

techniques and how they relate to one

another.
4. Based on an entity-relationship diagram, how can
you determine how many tables there will be in the
corresponding relational database?
5. Describe the process for converting entities in
each of the following relationships into relational
database structures:
a. One-to-one binary relationship.
b. One-to-many binary relationship.
c. Many-to-many binary relationship.
d. One-to-one unary relationship.
e. One-to-many unary relationship.
f. Many-to-many unary relationship.
g. Ternary relationship.
6. Describe the data normalization process including its
specific steps. Why is it referred to as a ''decompo-
sition process?''
7. Explain the following terms:
a. Functional dependency.
b. Determinant.
8. What characterizes unnormalized data? Why is such
data problematic?