Normalisation

Question 1

Define data normalisation, data redundancy and data consistency.

Answer 1

A staged mathematical process that removes repeated groups of data. A staged mathematical process that removes data duplication and inconsistencies.

Question 2

Define data redundancy and data consistency.

Answer 2

Data is redundant when it is duplicated unnecessarily. For example, a customer’s address should only be stored in one place, so it can be updated easily. Data must be consistent as it moves from input to processing to output. For example, if the designer decides the date should be in the format 16/03/17, it shouldn’t sometimes appear as 16th March 2017.

Question 3

A hospital unit uses a relational database. A patient is allocated to a ward and to a physiotherapist. One table in this database is structured as follows: tblWard (WardID, WardName, Capacity, FreeBeds) Give two other tables you could expect to see in this database.

Answer 3

Something like:

tblPatient (PatientID, FirstName, Surname, DateOfBirth, BloodType, Address, NextOfKin, WardID*, PhysioID*)

tblPhysio (PhysioID, FirstName, Surname, Phone)