Database Systems Lecture 1: Basic Concepts

Objective of the Course

• Introduces fundamentals of databases, focusing on design, construction, modification, and use.
• Emphasizes practical skills like creating Entity Relationship Diagrams (ERD) from case studies.
• Covers data normalization for effective database design.
• Instructs on constructing simple to moderately advanced SQL queries.

Grade Distribution

• Final Exam: 50%
• Mid-Term Exam: 25%
• Labs: 10%
• Practical Exam: 10%
• Assignments & Quizzes: 10%

What is a Database?

• Organized collection of related data, structured typically as records and tables with inter-table relationships.
• Data serves as the basic building block, represented as facts that hold implicit meaning, such as text, numbers, or figures.
• Records consist of related data items, exemplified by entries including ID, Name, and Area of Expertise.

Tables/Relations

• Tables consist of columns (Attributes) and rows (Tuples or Records).
• Example of a table:
  • Fields include ID, Name, and Area of Expertise.
  • Sample Records:
    • 12345, Sarah Ayyad, Machine Learning
    • 12355, Mohammed Mohammed, Radio Frequency

Traditional File-Based Systems

• Early approach to computerizing manual systems where each program maintains its own data.
• Characterized by several disadvantages:
  • Program Data Dependence: Metadata maintained per file by each program.
  • Data Redundancy: Separate copies of the same data across different systems.
  • Limited Data Sharing: No centralized data control.
  • Separation of Data: Data isolation with individual user copies.
  • Lack of Database Integrity: Inconsistent data management.
  • Lengthy Development Times: Increased time to develop applications.

The Database Approach

• Establishes a central repository of shared data managed by a controlling agent.
• Data is stored in a standard, efficient manner to improve accessibility and organization.

Applications of Database Systems

• Extensively used across various fields, including:
  • Banking: Managing transactions, accounts, and loans.
  • Airlines: Handling reservations and schedules.
  • Universities: Overseeing registrations, grades, and student information.
  • Sales: Keeping track of customers, products, and purchases.
  • Manufacturing: Managing production, inventory, and orders.
  • Human Resources: Storing employee records, salaries, and tax deductions.
  • Telecommunications: Monitoring calls, billing, and network information.
  • Geographic Information Systems (GIS): Storing and analyzing maps and weather data.

Basic Definitions

• Database Management System (DBMS): Software for creating and managing databases, facilitating systematic data interaction.
  • Offers tools for creating, retrieving, updating, and managing data efficiently.
  • Acts as an interface between the database and users or application programs, ensuring data organization and access.
• Database System: Combination of DBMS software and the associated data itself.

Course Objectives

• Introduction to fundamental concepts of databases including design, construction, and modification.
• Skills development in constructing Entity-Relationship Diagrams (ERD) using practical case studies.
• Application of normalization techniques for effective database design.
• Creation of simple to moderately advanced Structured Query Language (SQL) queries.

Grade Distribution

• Final Exam contributes 50%.
• Mid-Term Exam accounts for 25%.
• Labs represent 10%.
• Practical Exam comprises 10%.
• Assignments & Quizzes make up the remaining 10%.

Understanding Databases

• Data: Fundamental building block of databases, encompasses facts like text and numbers.
• Record: A collection of related data items, represented in tabular format.

Table Structure

• Table/Relation: Consists of records (tuples) organized into columns (attributes).
• Example of a table showcasing records with attributes such as Id, Name, and Area of expertise.

Definition of a Database

• An organized collection of related data, typically structured as records or tables, fostering relationships among them.

Traditional File-Based Systems

• Early computerized systems where each program manages its own data.
• Disadvantages include:
  • Program Data Dependence: Each program retains its own metadata.
  • Data Redundancy: Separate copies of data exist across programs.
  • Limited Data Sharing: Absence of centralized data control.
  • Isolation of Data: Users operate with individual data copies.
  • Lack of Database Integrity: No assurance of data accuracy or consistency.
  • Lengthy Development Times associated with data management.

Database Approach

• A solution to traditional file-based systems, providing a central repository for shared data.
• Data is administered by a controlling agent and stored in a standardized format.

Database System Applications

• Databases are integrated into numerous sectors including:
  • Banking: Transactions, accounts, and loans management.
  • Airlines: Reservations and schedule organization.
  • Universities: Registration, grading, and student information management.
  • Sales: Customer, product, and purchase tracking.
  • Manufacturing: Oversight of production, inventory, and orders.
  • Human Resources: Management of employee records and salary information.
  • Telecommunications: Call records and billing processes.
  • Geographic Information Systems (GIS): Analyzation of maps, weather data, and satellite imagery.

Database Management System (DBMS)

• A computerized record-keeping system that facilitates database management and offers a systematic method for data manipulation.
• Functions as an interface between the database and users, ensuring organized data access.

Components of Database Systems

• Composed of DBMS software, the data itself, and sometimes application programs.

Popular DBMS Examples

• Microsoft Access is noted as a widely used DBMS.

Advantages and Features of DBMS

• Manages data redundancy while ensuring security from unauthorized access.
• Provides backup, recovery options, and diverse data views for different users.
• Enforces integrity constraints ensuring data consistency.
• Provides program-data independence through metadata management.
• Facilitates concurrent data management and offers user-friendly graphical interfaces.

Disadvantages of DBMS

• High costs associated with implementation and maintenance.
• Requires expertise for effective use.
• Vulnerability to software failures which may jeopardize data handling.
• Potential compatibility issues with differing DBMS software.