4.1 Quality data is needed for useful information to be extracted from a database - NSC Information Technology - Question 4 - 2016 - Paper 2
Question 4
4.1 Quality data is needed for useful information to be extracted from a database.
List THREE characteristics of quality data.
4.2 While testing the database one ... show full transcript
Worked Solution & Example Answer:4.1 Quality data is needed for useful information to be extracted from a database - NSC Information Technology - Question 4 - 2016 - Paper 2
Step 1
List THREE characteristics of quality data.
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Accurate: Data should reflect the true situation and be free from errors.
Up to date/Current: Data must be timely and accurately represent the current state of the information.
Relevant: The data should be applicable and meaningful for the intended purpose.
Step 2
What is an update anomaly?
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An update anomaly occurs when changes made to a data item in a table do not propagate to all related records in the database. This can lead to data inconsistency, as the related records may not be updated correctly, leaving some information outdated or incomplete.
Step 3
What is the advantage of running a DBMS on a server?
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A DBMS on a server allows for centralized management of the database, enabling multiple users to access and manipulate the database concurrently without direct access to the database itself. This enhances security and simplifies database administration.
Step 4
What is the responsibility of a database administrator?
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A database administrator is responsible for managing and maintaining the database, which includes overseeing user access, optimizing performance, and ensuring data security and integrity.
Step 5
State TWO tasks specific to the job description of a database analyst.
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Designing and implementing database queries: This involves creating, modifying, and optimizing SQL queries to ensure efficient data retrieval.
Analyzing data requirements: A database analyst assesses the needs and usage of data within the organization, ensuring that the database structure meets the users' needs.
Step 6
Suggest a solution to scale down the size of the database without losing the functionality of the database.
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A potential solution could be to implement data warehousing techniques such as partitioning or normalization, which helps in organizing data more efficiently and reducing redundancy, thus minimizing the overall size of the database.
Step 7
Explain why the current design of the database will not allow for the same stand to be allocated to more than one exhibitor.
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The StandNo field in the tblStands table is the primary key, which means it must contain unique values for each record. As a result, the database design enforces that no two records can have the same StandNo, effectively preventing multiple exhibitors from being allocated the same stand.
Step 8
Display the stand numbers that require a plug point.
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SELECT StandNo FROM tblStands WHERE PlugPoint = 'Yes';
Step 9
Allocate an additional assistant to each stand.
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UPDATE tblStands SET Assistants = Assistants + 1;
Step 10
Remove the stand with stand number B02 from tblStands.
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DELETE FROM tblStands WHERE StandNo = 'B02';
Step 11
Provide the output for the SQL statement.
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