Define database and list three business applications and five advantages over paper systems.

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Question 17

a) i) Define Database (2mks)
A database is an organized collection of structured information, or data, typically stored electronically in a computer system. It is designed for efficient storage, retrieval, and management of data.

a) ii) Give three areas where databases may be used in business (3mks)

• Customer Relationship Management (CRM): Storing customer details, purchase history, and interactions.
• Inventory Management: Tracking stock levels, product information, and supplier details.
• Financial Accounting: Managing transactions, ledgers, and financial records.
• Human Resources: Storing employee information, payroll, and performance data.

b) i) State five advantages that modern database systems have over paper-based systems (5mks)

• Reduced Data Redundancy: Data is stored once, minimizing duplication.
• Improved Data Consistency: Ensures that data is uniform and accurate across the system.
• Enhanced Data Security: Provides mechanisms for access control and data protection.
• Easier Data Sharing: Multiple users can access and share data concurrently.
• Faster Data Retrieval and Updates: Allows quick searching, sorting, and modification of data.
• Better Data Integrity: Enforces rules to maintain the quality and reliability of data.
• Reduced Storage Space: Digital storage is more compact than physical paper records.
• Data Backup and Recovery: Facilitates easy backup and restoration of data in case of loss.

b) ii) STATE five major functions of DBMS in computerized information processing (5 mks)

• Data Definition: Allows users to define the structure of the database, including data types, relationships, and constraints.
• Data Manipulation: Provides tools for adding, deleting, modifying, and retrieving data from the database.
• Data Security and Integrity: Manages user access, permissions, and ensures data accuracy and consistency through validation rules.
• Data Storage Management: Handles the physical storage of data on disk and manages access to it.
• Data Backup and Recovery: Provides utilities to create backups of the database and restore it in case of system failure or data loss.
• Concurrency Control: Manages simultaneous access to the database by multiple users, preventing conflicts and ensuring data consistency.

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Question 18

a) Describe the octal number system (2mks)
The octal number system is a base-8 number system, meaning it uses eight distinct digits (0, 1, 2, 3, 4, 5, 6, 7) to represent numbers. Each position in an octal number represents a power of 8.

b) Convert each of the following to the number system indicated:

i) $111.101_2$ to decimal (2 marks)
To convert a binary number to decimal, multiply each digit by its corresponding power of 2.

$$111.101_2 = (1 \times 2^2) + (1 \times 2^1) + (1 \times 2^0) + (1 \times 2^{-1}) + (0 \times 2^{-2}) + (1 \times 2^{-3})$$ $$= (1 \times 4) + (1 \times 2) + (1 \times 1) + (1 \times 0.5) + (0 \times 0.25) + (1 \times 0.125)$$ $$= 4 + 2 + 1 + 0.5 + 0 + 0.125$$ $$= 7 + 0.625$$ $$= \boxed{\text{}7.625_{10}\text{}}$$

ii) $14.6875_{10}$ to binary (2 marks)
To convert a decimal number to binary, convert the integer and fractional parts separately.

• Integer part (14): Divide by 2 and collect remainders. $14 \div 2 = 7$ R 0 $7 \div 2 = 3$ R 1 $3 \div 2 = 1$ R 1 $1 \div 2 = 0$ R 1 Reading remainders from bottom up: $1110_2$

• Fractional part (0.6875): Multiply by 2 and collect integer parts. $0.6875 \times 2 = 1.375 \rightarrow 1$ $0.375 \times 2 = 0.75 \rightarrow 0$ $0.75 \times 2 = 1.5 \rightarrow 1$ $0.5 \times 2 = 1.0 \rightarrow 1$ Reading integer parts from top down: $0.1011_2$

Combining the integer and fractional parts:

$$14.6875_{10} = \boxed{\text{}1110.1011_2\text{}}$$

c) Convert the number $-17_{10}$ into 8-bit i) Signed magnitude representation (2 marks)