Chapter 2, Problem 2.1RQ

Program Plan Intro

Relational model:

• In the relational model, data are organized in tables, which consist of rows and columns.
  • A data in a row or column of a table are called fields.
  • Fields in a database table are also referred as attributes of a database object.
    • A group of related fields are called as a record, which is also called as database object or entity.
    • A group of records are called a table.
    • Keys in a relational database table refer to a key field.
      • To identify each record in a table, there must be at least one data field that should be unique. That is, a corresponding data field of every record should be unique.
      • Therefore, key field is used to identify the unique record from a collection of records.
• For example,
  • Consider a database table named “Student” that contains the student details such as “StudentID”, “StudentName”, “Marks”, which are the fields of the table, and they are altogether called as records.
    • The “StudentID” contains the registration number of students, “StudentName” contains name of students, and “Marks” contain the computer science marks of each student.

Explanation of Solution

Importance of relational model:

Relational model is important, due to the following reasons

• It is important because it acts as the universal model to store the data in computers and it can be easily available.
• Specific values can be easily accessed through a database.
• It can be used for the designing and implementation of commercial database.
• Its data storage capacity can be extended and it won’t depend on physical organization.
• It includes the Structured Query Language (SQL).
• It includes various features like reduced data redundancy, portability, data integrity, constraining the input and many others.