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 o... 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: The data must represent the real-world situation it is intended to portray.
Up to date/Current: Data should be updated regularly to reflect the latest information.
Complete: All necessary information must be included without any missing pieces.
Step 2
What is an update anomaly?
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An update anomaly occurs when changes to data in one table do not propagate to related records in multiple tables. This leads to inconsistencies and incomplete updates, causing data integrity problems.
Step 3
What is the advantage of running a DBMS on a server?
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Running a DBMS on a server allows multiple users to access the database concurrently, improving collaboration and data management efficiency. It also provides enhanced security and centralized control over the database.
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. This includes ensuring data integrity, security, and availability, as well as performing backups and updates as needed.
Step 5
State TWO tasks specific to the job description of a database analyst.
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Analyzing data requirements: A database analyst identifies business needs and gathers requirements to design the database schema accordingly.
Optimizing performance: They manage queries and database structures to improve the speed and efficiency of data retrieval.
Step 6
Suggest a solution to scale down the size of the database without losing functionality.
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One solution could be to implement data warehousing or data partitioning techniques. This involves archiving old data that is not actively used, thus reducing the size of the operational database while still retaining important historical data.
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 current design of the database employs a unique primary key for the StandNo field in the tblStands table. This means each stand can only be associated with one exhibitor, preventing any overlap or double allocation.
Step 8
Display the stand numbers that require a plug point.
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SELECT StandNo FROM tblStands WHERE PlugPoint=True;
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 the database.
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DELETE FROM tblStands WHERE StandNo = 'B02';
Step 11
Give the exact output for the SQL statement.
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The output would display three columns: CompanyName, NumStands, and SumAssistants, with the corresponding values as follows:
