4.1 Consider the entity relationship diagram (ERD) below and answer the questions that follow - NSC Information Technology - Question 4 - 2023 - Paper 2
Question 4
4.1 Consider the entity relationship diagram (ERD) below and answer the questions that follow.
(a) What is the purpose of an ERD?
(b) Choose the most suitable term... show full transcript
Worked Solution & Example Answer:4.1 Consider the entity relationship diagram (ERD) below and answer the questions that follow - NSC Information Technology - Question 4 - 2023 - Paper 2
Step 1
What is the purpose of an ERD?
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
An ERD provides a visual representation of how the data/tables are linked in a relational database. It helps in understanding the structure and relationships within the data.
Step 2
Choose the most suitable term from the list below for the part of the ERD above that is indicated by (a).
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The answer is (a) Entity.
Step 3
Choose the most suitable term from the list below for the part of the ERD above that is indicated by (b).
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The answer is (b) One.
Step 4
Choose the most suitable term from the list below for the part of the ERD above that is indicated by (c).
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The answer is (c) Relationship.
Step 5
Choose the most suitable term from the list below for the part of the ERD above that is indicated by (d).
97%
117 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The answer is (d) Many.
Step 6
Name ONE other requirement of a primary key.
97%
121 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
A primary key must be non-null; it cannot contain empty or null values.
Step 7
Critically analyse the design of the tblPlaylist table by explaining why the table does not adhere to the rules of normalisation.
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The tblPlaylist table does not adhere to normalisation rules for two main reasons:
There are no primary keys defined, which is essential for maintaining unique records.
The table contains repeating fields; for instance, the number of songs can be derived or recalculated, making it dependent on other fields, which violates normalization principles.
Step 8
Give a reason why it is more suitable to save the playlist information in a database rather than in a text file.
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Using a database allows for easier filtering of information, performing queries, and maintaining the data efficiently compared to a static text file.
