Fundamentals of Database Systems Module 1: Introduction PDF

Fundamentals of Database Systems Module 1: Introduction  Basic Definitions ◉ Database: A collection of related data ◉ Data: Known facts that can be recorded and have an implicit meaning ◉ Database Management System (DBMS): A software package/ system to store and manage databases ◉ EX. Oracl,sq...

Fundamentals of Database Systems Module 1: Introduction  Basic Definitions ◉ Database: A collection of related data ◉ Data: Known facts that can be recorded and have an implicit meaning ◉ Database Management System (DBMS): A software package/ system to store and manage databases ◉ EX. Oracl,sqlserver,access,mongoDB Database Management System (DBMS)  Database Management System (DBMS) ◉ Typical functionalities include: 1. Define a database (tables, datatypes, constraints, and structures) 2. Retrieve from/query a database 3. Update a database (insert, modify or delete) 4. Keeping the data valid 5. Allowing multiple users and applications to access and share the database. ◉ Other functionalities include preventing unauthorized access and displaying and visualizing the data.  Database ◉ Models a real-world enterprise: ◉ 1. Entities: Entities are specific things or objects in the mini-world that are represented in the database ◉ 2. Attributes: Properties used to describe an entity ◉ 3. Relationships: Relates two or more distinct entities with a specific meaning  Query and Update ◉ 1. Query: Retrieve from tables 2. Update: Change in tables  Example 1: ◉ Course management system: ◉ Students, courses, sections, and professors ◉ Professors teach sections ◉ Students register in sections. ◉ Courses have sections ◉ Students have names, students IDs, phone numbers..  Example 1: ◉ Course management system: ◉ Students, courses, sections, and professors Entities ◉ Professors teach sections ◉ Students register in sections. Relationships ◉ Courses have sections ◉ Students have names, students IDs, phone numbers.. Attributes Example 1  Example 1: ◉ Query examples: 1. Return all students 2. Classes offered in Spring of 08 3. Courses taught in the CS department  Example 1: ◉ Update examples: 1. Change Smith major to CE 2. Add new math course 3. Change instructor for CS1310 from Anderson to Kruth  Actors on the Scene ◉ Important people 1. Database Administrator (DBA): Manages the database 2. Database Designer: Specify the data and structures 3. End User: Users who access the database 4. Systems analysts: Determine the requirements for end users 5. Application programmers: Write code to allow end user to access database based on the requirements from systems analysts. Actors on the Scene ◉ For the car repair shop example: 1. Database Administrator (DBA): Make sure DB is running with no issues. Grant access to database if needed. 2. Database Designer: Specify the tables and the attributes needed for each table 3. End User: Person at the front desk. Maybe mechanics 4. Systems analysts: Specify what the EU needs to see 5. Application programmers: Write the programmers for EU Schema and State ◉ Database Schema: The description of a database. Includes descriptions of the database structure, data types, and the constraints on the database. ◉ Schema Diagram: An illustrative display of (most aspects of) a database schema. ◉ Database State: The actual data stored in a database at a particular moment in time. This includes the collection of all the data in the database. ◉ Also called database instance  Schema Diagram Human Resource & Order Entry Schema  Schema Diagram sales history ( SH ) Schema Database State: Example