A small local business operating from a single site store their business data in a database with two tables called tblClients and tblOrders - NSC Information Technology - Question 4 - 2019 - Paper 2
Question 4
A small local business operating from a single site store their business data in a database with two tables called tblClients and tblOrders.
The table design for th... show full transcript
Worked Solution & Example Answer:A small local business operating from a single site store their business data in a database with two tables called tblClients and tblOrders - NSC Information Technology - Question 4 - 2019 - Paper 2
Step 1
4.1 No primary key is indicated.
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Answer
The tblClients and tblOrders tables lack primary keys, which are crucial for ensuring data integrity and the uniqueness of each record. A primary key is essential to uniquely identify each entry, preventing duplicate data.
Step 2
4.2 Only orders with the value of an amount of at least R500,00 will be inserted into the tblOrders table. Suggest a data validation technique that can be used to enforce this condition.
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A range check validation rule can be implemented on the Amount field to ensure that only values greater than or equal to R500,00 can be entered into the tblOrders table.
Step 3
4.3.1 Which fields can be used to set a relationship between the tables?
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The fields that can establish a relationship are ClientSAID from the tblClients table and ClientSAID_Ref from the tblOrders table.
Step 4
4.3.2 Identify the type of relationship which will be formed AND indicate the table that will appear on each side of the relationship.
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A one-to-many relationship will be formed, where tblClients will be on the 'one' side and tblOrders will be on the 'many' side.
Step 5
4.4 Evaluate why this suggestion would lead to a poor table design.
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Adding the ClientAge field introduces data redundancy since ClientAge can be derived directly from the ClientSAID field, which already contains the birth date information encoded in it. This not only wastes storage space but also poses risks of inconsistent data.
Step 6
4.5 Suggest whether the business should use a desktop or server database management system. Motivate your answer.
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A server DBMS would be more scalable and provide better accessibility, especially if the business seeks to expand in the future. However, a desktop DBMS may suffice considering the small size of the business. Choosing either should depend on future growth expectations.
Step 7
4.6.1 Is the error message above caused by a syntax, runtime or logical error?
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The error message is caused by a runtime error, specifically occurring when trying to insert a record that references a non-existent ClientSAID in the tblClients table.
Step 8
4.6.2 Name the database design concept related to the error message above.
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The concept related to this error is referential integrity, which ensures that relationships between tables remain consistent.
Step 9
4.7 Define the term mirroring.
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Mirroring is a data protection technique that creates a duplicate copy of data in real-time, ensuring that there is always an identical version available in case of a failure in the primary data source.
Step 10
4.8 Suggest TWO guidelines for a good password policy in terms of the compilation of passwords.
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Use different passwords for different accounts to enhance security.
Make passwords long and complex, including a mixture of upper and lower case letters, numbers, and symbols.
Step 11
4.9 What is meant by the term invisible data capturing?
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Invisible data capturing refers to the process of collecting personal data from users without their explicit knowledge or consent, often through tracking technologies.
Step 12
4.10 Explain the concept of data mining.
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Data mining is the practice of examining large datasets to discover patterns, trends, and relationships that can be used for decision-making, usually in the context of business intelligence.
Step 13
4.11 Briefly discuss how an audit trail can be used to assist the auditing firm in their investigation.
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An audit trail provides a comprehensive record of all transactions and changes made in the database, allowing auditors to trace any discrepancies back to their origin, thereby ensuring accountability and transparency.
Step 14
4.12 Explain how record locking works.
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Record locking prevents multiple users from making changes to the same data at the same time, ensuring data integrity. When a record is being edited, it is locked, and other users are prevented from editing it until the first user finishes.
