Database Reference
In-Depth Information
2.2.4 Analyze Collected Information
To identify the information that is useful for designing the database, the analysis will focus on the
following areas.
Identify objects to keep track of
: From the class schedule, we can identify the objects:
class
,
class time
,
classroom
,
building
,
instructor
, and
course
. Both the Class Registration Form and
Transcript indicate that the
student
and
semester
objects should also be included. By examining
the results of the interviews and the observation of the registration process, those are the objects
to keep track of.
Identify speciications of objects
: Let us examine each of the objects identiied in the above step.
◾
Class
: According to the class schedule, a class can be described by its ID, the course content
to be covered in this class, the class meeting time, the instructor, and the classroom. he
middle section of the Transcript gives more description about the
class
object. here, a class
is described by its course ID, course name, and the student's grade.
◾
Course
: Course catalog indicates that we can use course ID, credit, prerequisite, and course
description to describe the
course
object.
◾
Classroom and Building
: From the class schedule, a classroom can be speciied by its num-
ber and the name of the building. By observing how data are used in a business process, we
should also include the capacity of the classroom as the attribute of the
classroom
object.
he
building
object can be described by its ID and name.
◾
Student
: From the Transcript, the object
student
can be described by the ID, irst name,
and last name. he Class Registration Form also shows the student's major, which is also a
characteristic of the student.
◾
Faculty
: In the class schedule, the object
instructor
is described by the last name. hrough
the interviews, we found out that the faculty members need to be related to their advisees. It
is better to describe a faculty member by both the last name and the irst name so that it is
easier for advisees to identify their advisors in case some professors have the same last name.
From the course catalog, you can ind which department a professor belongs to.
◾
Class Time
: he object
class time
is speciied by time blocks and weekdays as shown in the
class schedule.
◾
Semester
: According the Class Registration Form and Transcript, this object can be
described by its name.
Identify type and amount of data
: Let us check the type of data used in each object.
◾
For the
class
object, the class ID can be the integer data type. he class time, course name,
instructor, and grade can all be character strings. Each semester, there may be hundreds of
classes scheduled. he data accumulated for many years of classes can add up to a signiicant
number.
◾
For the
student
object, the student ID is the integer type. he irst name, last name, and major
can be described by character strings. Hundreds or even thousands of new students may be
added to the
student
table each semester. he growth rate of data for this object is high.
◾
For the
course
object, the data type for credit can be an integer. he course ID, prerequisite,
and course description can all be deined as character strings. he growth rate of data is
relatively low. Each year, only some courses are added or modiied.
