Chapter 10 Database and Data Modelling

Question 1

What does file-based approach mean?

Answer 1

File-based approach means to gather data into one file.

Question 2

What are the disadvantages of file-based approach?

Answer 2

In file-based approach there is data redundancy, lack of data privacy and lack of data validation.

Question 3

What does data dependency concerns mean?

Answer 3

Data dependency concerns is when a file is changed for example an extra column is added and the programs accessing this file have to be re-written so that they wouldn’t get the wrong data.

Question 4

What is a database approach?

Answer 4

The database approach is an implementation according to the rules of a theoretical model

Question 5

What is the name of the theoretical models name used in the database approach?

Answer 5

The ANSI three-level architecture.

Question 6

Which are the three levels in the ANSI three-level architecture?

Answer 6

Internal level - Accommodates any changes that might be needed in the storage medium
Conceptual level - A person who uses the DBMS to customize the database to suit user and programmer requirements
External level

Question 7

What is the external level?

Answer 7

The external level is the level from which most of the users control the database

Question 8

What is a relational?

Answer 8

A relational is a special type of table which is used to show the entities functions for example the date of production of a car.