Untitled Quiz

Study Notes

Fundamentals of Database Systems - Module 1: Introduction

Database: A collection of related data.
Data: Known facts, recorded with implicit meaning.
Database Management System (DBMS): Software for storing and managing databases.
- Examples: Oracle, SQL Server, Access, MongoDB.
Database System Components:
- DBMS Software: Processes queries, accesses stored data.
- Stored Database: The data itself.
- Stored DB Definition (Metadata): Describes the database structure.
- Users (Application Programs): Interact with the system.
DBMS Functionalities:
- Defining a database (tables, data types, constraints)
- Querying a database (retrieving data)
- Updating a database (inserting, modifying, deleting)
- Ensuring data validity.
- Allowing multiple users/applications to access and share the database.
- Preventing unauthorized access.
- Displaying and visualizing data.
Database Models:
- Entities: Specific things/objects in the mini-world, represented in the database.
- Attributes: Properties used to describe entities.
- Relationships: Links between entities with specific meanings.
Query and Update:
- Query: Retrieving data from tables.
- Update: Modifying data in tables.
Example 1: Course Management System:
- Entities: Students, courses, sections, professors
- Relationships: Professors teach sections, students register in sections, courses have sections.
- Attributes: Student names, IDs, phone numbers; course names; section information.
Example 1 - Data Structures (Tables):
- STUDENT: Name, Student number, Class, Major
- COURSE: Course name, Course number, Credit hours, Department
- SECTION: Section identifier, Course number, Semester, Year, Instructor
Example 1 - Query and Update Examples:
- Returning all students.
- Classes offered in a specific semester (e.g., Spring 08).
- Courses taught in a specific department (e.g., CS).
- Changing a student's major.
- Adding a new course.
- Changing an instructor's assignment.
Actors in Database Systems:
- Database Administrator (DBA): Manages the database.
- Database Designer: Defines the data organization and structure.
- End User: User accessing the database.
- Systems Analysts: Determine user needs.
- Application Programmers: Build applications for end users.
Schema and State:
- Database Schema: Description of a database structure, data types, and constraints.
- Schema Diagram: Illustrative display of the database schema.
- Database State (Instance): The actual data in the database at a given time, Includes current data values for all attributes.
Schema Diagram Example: Human Resource and Order Entry Schema (Presented as a diagram - cannot be summarized textually).
Sales History Database (SH): Another schema diagram (presented as a diagram - cannot be summarized textually).
Database State Example (Table Data): Sample data for "Player," "Game," and "League" tables and other tables including data about players, date of birth, country, active/inactive status, games, etcetera.