The tour company requires the use of a database management system to store details of tours and tour guides - NSC Information Technology - Question 4 - 2017 - Paper 2
Question 4
The tour company requires the use of a database management system to store details of tours and tour guides.
4.1 Which ONE of the following is an example of a DBMS?... show full transcript
Worked Solution & Example Answer:The tour company requires the use of a database management system to store details of tours and tour guides - NSC Information Technology - Question 4 - 2017 - Paper 2
Step 1
4.1 Which ONE of the following is an example of a DBMS?
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Answer
The correct answer is Oracle. Oracle is a widely used database management system known for its robust features and capabilities in managing large amounts of data.
Step 2
4.2 Name TWO aspects of database design that should be addressed to ensure effective functionality.
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Answer
Two important aspects of database design include:
Data integrity: Ensuring that the data is accurate and reliable.
Data security: Protecting the data from unauthorized access or breaches.
Step 3
4.3.1 Explain what a record in a database is.
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A record in a database refers to a collection of fields that contain data about a specific entity. It represents a single row of data within a table, where each field corresponds to a particular attribute of the entity.
Step 4
4.3.2 Identify ONE field where the data type needs to be changed AND suggest a more suitable data type.
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The StartDate or EndDate field can be changed from text to a DateTime data type. This will allow for proper date manipulation and validation.
Step 5
4.3.3(a) Explain what an update anomaly is, using the tour guide Kajal Singh as an example.
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An update anomaly occurs when inconsistencies arise in the database due to the same data being stored in multiple places. For example, if Kajal Singh's phone number changes, all records where she is listed as the tour guide would need to be updated to reflect the new number. Failing to do this would leave some records with outdated contact information.
Step 6
4.3.3(b) Explain the basic steps that should be followed when the tblTours table has to be normalised.
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To normalize the tblTours table, the following steps should be taken:
Identify and eliminate redundancy: Determine which data fields cause duplication and remove them by creating new tables.
Establish primary keys: Ensure each table has a unique identifier (primary key) for each record.
Define relationships: Create appropriate relationships between the new tables using foreign keys to maintain data integrity.
Step 7
4.3.4 What is the result after executing the statement DELETE FROM tblTours?
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The execution of the SQL statement DELETE FROM tblTours will remove all records from the tblTours table. However, the table structure will remain intact, allowing for new records to be added in the future.
Step 8
4.4 Briefly explain how the use of parallel data sets prevents loss of data.
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Using parallel data sets allows for backup copies of data. If one set fails or becomes corrupted, the other set maintains the integrity of the data, thus preventing loss.
Step 9
4.5 Explain what data mining is.
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Data mining is the process of using software tools to analyze large data sets to identify patterns and extract valuable information. It helps organizations make informed decisions based on trends found within the data.
Step 10
4.6 Explain how SQL injection can be used as a hacking tool.
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SQL injection involves inserting malicious SQL statements into a query through input fields. If a web application does not properly sanitize inputs, attackers can manipulate the database to gain unauthorized access to sensitive data or perform destructive actions.
Step 11
4.7.1 Give TWO reasons why distributed databases are used.
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Distributed databases are used because:
Improved reliability: They offer data redundancy and fault tolerance.
Increased performance: Data can be accessed and processed in parallel across multiple locations, enhancing speed and efficiency.
Step 12
4.7.2 Name the TWO models that distributed databases are based on and explain how data on various servers remain up to date and synchronised.
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The two models are:
Replication model: All data is copied across multiple servers. Synchronization is achieved through regular updates to ensure consistency.
Partitioning model: Data is divided among servers. Synchronization occurs during transactions to ensure that consistent views of the data are accessible across servers.
