Suppose that we have the following requirements for a university database that is used to keep track of students' transcripts: a. The university keeps track of each student's name (SNAME), student number (SNUM), social security number (SSN), current address (SCADDR) and phone \((\mathrm{SCPHONE}),\) permanent address \((\mathrm{SPADDR})\) and phone \((\mathrm{SPPHONE}),\) birth date \((\mathrm{BDATE})\) \(\operatorname{sex}(\operatorname{sex}), \text { class (cLass) (freshman, sophomore, } \ldots, \text { graduate }),\) major depart ment (MAJORCODE), minor department (MINORCODE) (if any), and degree program \(\left(p_{R O C}\right)(B, A,, B, S, \ldots, P H, D,) .\) Both sss \(N\) and student number have unique val. ues for each student. b. Each department is described by a name (DNAME), department code (DCOOE), office number (DOFFICE), office phone (DPHONE), and college (DCOLLECE). Both name and code have unique values for each department. c. Each course has a course name (cNAME), description (cDESC), course number (CNUM), number of semester hours (cREDIT), level (LEVEL), and offering depart. ment (coept). The course number is unique for each course. d. Each section has an instructor (INAME), semester (SEMESTER), year (YEAR), course (seccourse), and section number (secwum). The section number distinguishes different sections of the same course that are taught during the same semester/ year; its values are \(1,2,3, \ldots,\) up to the total number of sections taught during each semester. e. \(A\) grade record refers to a student \((\operatorname{ss} N),\) a particular section, and a grade \((\mathrm{CRADE})\) Design a relational database schema for this database application. First show all the functional dependencies that should hold among the attributes. Then design relation schemas for the database that are each in \(3 \mathrm{NF}\) or BCNF. Specify the key attributes of each relation. Note any unspecified requirements, and make appropriate assumptions to render the specification complete.

Step by step solution

01

Identifying the Entities

The entities in this case would be: Student, Department, Course, Section, and Grade record. Each entity should represent an object that is essential in our database and has certain properties (attributes) that we want to record.

02

Identifying the Attributes

The attributes of each entity would be as follows: \n- Student: SNUM, SNAME, SSN, SCADDR, SCPHONE, SPADDR, SPPHONE, BDATE, sex, class, MAJORCODE, MINORCODE, PROC. \n- Department: DNAME, DCOOE, DOFFICE, DPHONE, DCOLLECE. \n- Course: CNUM, CNAME, CDESC, cREDIT, LEVEL, coept. \n- Section: secnum, INAME, SEMESTER, YEAR, seccourse. \n- Grade record: SSN, secnum, GRADE.

03

Identifying Functional Dependencies

Functional Dependencies would include: \n- Student: SNUM -> SSN, SNAME, SCADDR, SCPHONE, SPADDR, SPPHONE, sex, class, MAJORCODE, MINORCODE, PROC. \n- Department: DCOOE -> DNAME, DOFFICE, DPHONE, DCOLLECE. \n- Course: CNUM -> CNAME, CDESC, cREDIT, LEVEL, coept. \n- Section: secnum -> INAME, SEMESTER, YEAR, seccourse. \n- Grade record: SSN, secnum -> GRADE.

04

Normalization

The relations will be normalized to either 3NF or BCNF by ensuring that each entity is in 1NF (each column contains only indivisible values), is in 2NF (no non-prime attribute in the relation schema is functionally dependent on a part of any of its candidate keys) and is in 3NF (all determinants are candidate keys) or BCNF (every nontrivial functional dependency's determinant is a superkey). The primary keys would be SSN and SNUM for Students, DCOOE for Department, CNUM for Course, secnum for Section, and combination of SSN and secnum for Grade record.

05

Assumptions

Since it is not mentioned, for simplicity, we assume that the college attribute (DCOLLECE) for the department entity pertains to the university's various colleges rather than referring to other universities.

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