INF2603 ASSIGNMENT 4 SOLUTIONS 2022
QUESTION 1
Briefly explain what is meant by each of the following terms in a database design context and
provide an example. (explanation = 2, example =1 mark):
a. Granularity
Granularity concerns the ability to represent and operate on different levels of detail in data,
information, and knowledge that are located at their appropriate level. The entities are
described relative to that level, which may be more coarse-grained or concern fine-grained
details. For example devising these ordered levels of granularity in a granular perspective are
either determined by the laws of nature or are a resultant of human cognition to divide the data,
information, or knowledge.
b. Ternary relationships
When there are exactly three entity sets participating in a relationship then such type of
relationship is called ternary relationship. Example of Ternary Relationship
In the real world, a patient goes to a doctor and doctor prescribes the medicine to the patient,
three entities Doctor, patient and medicine are involved in the relationship “prescribes”
c. Overlapping subtypes
Overlapping subtypes are subtypes that contain non-unique subsets of the supertype entity set;
that is, each entity instance of the supertype may appear in more than one subtype. For example,
in a university environment, a person may be an employee or a student or both.
d. Cloud database
A cloud database is a type of database service that is built, deployed and delivered through a
cloud platform. It is primarily a cloud Platform as a Service (PaaS) delivery model that allows
organizations, end users and their applications to store, manage and retrieve data from the
cloud. Examples of Cloud Databases PostgreSQL is a traditional, relational SQL database that
may be cloud hosted. It provides the robust relational integrity some applications require but is
an older technology, is non-distributed, inflexible, and less scalable.
QUESTION 1
Briefly explain what is meant by each of the following terms in a database design context and
provide an example. (explanation = 2, example =1 mark):
a. Granularity
Granularity concerns the ability to represent and operate on different levels of detail in data,
information, and knowledge that are located at their appropriate level. The entities are
described relative to that level, which may be more coarse-grained or concern fine-grained
details. For example devising these ordered levels of granularity in a granular perspective are
either determined by the laws of nature or are a resultant of human cognition to divide the data,
information, or knowledge.
b. Ternary relationships
When there are exactly three entity sets participating in a relationship then such type of
relationship is called ternary relationship. Example of Ternary Relationship
In the real world, a patient goes to a doctor and doctor prescribes the medicine to the patient,
three entities Doctor, patient and medicine are involved in the relationship “prescribes”
c. Overlapping subtypes
Overlapping subtypes are subtypes that contain non-unique subsets of the supertype entity set;
that is, each entity instance of the supertype may appear in more than one subtype. For example,
in a university environment, a person may be an employee or a student or both.
d. Cloud database
A cloud database is a type of database service that is built, deployed and delivered through a
cloud platform. It is primarily a cloud Platform as a Service (PaaS) delivery model that allows
organizations, end users and their applications to store, manage and retrieve data from the
cloud. Examples of Cloud Databases PostgreSQL is a traditional, relational SQL database that
may be cloud hosted. It provides the robust relational integrity some applications require but is
an older technology, is non-distributed, inflexible, and less scalable.
