Chapter 2, Problem 3PE

Explanation of Solution

Primary key of a relation:

• A primary key is a special column of a relation used for uniquely identifying a relation.
• The primary key can be one column or combination of columns. The primary key will uniquely identify all the records of a table.
• The features of a primary are:
  • The primary key contains a unique value for each row of data.
  • The primary key column cannot contain null values.

Identifying the primary key in the given database:

• The time_slot relation is given below,

Time_slot (time_slot_id, day, start_time, end_time)

• The class section has an associated time_slot_id.
• The time_slot gives the information on which days of the week and what times a particular “time_slot_id” meets...