What is the difference between a DBMS and a traditional file system?

A DBMS organizes data centrally and provides controlled access, reduced redundancy, data integrity, security, and easier multi-user sharing compared with separate file-based storage.

What is the three-schema architecture in a database system?

It separates the database into external user views, a conceptual logical schema, and an internal physical storage schema, helping achieve data independence.

What are primary keys, superkeys, and referential integrity in relational databases?

A superkey uniquely identifies a row; a primary key is a selected minimal superkey. Referential integrity requires foreign-key values to reference valid rows in the related table.

Free Course Image Database Management Systems

Free online course Database Management Systems

Duration of the online course: 5 hours and 21 minutes

(11)

Build job-ready database skills with this free online course—learn DBMS fundamentals, ER modeling, relational concepts, and architecture with practice quizzes.

In this free course, learn about

Why DBMSs outperform file systems: reduced redundancy, shared access, better integrity & security
Core DBMS characteristics: data abstraction, independence, concurrency control, recovery, metadata catalog
Database user roles: DBA, designers, developers, end users; DBA handles resources and access authorization
Evolution of database applications and major shifts in DBMS technology over time
Fundamentals of data models; conceptual models use entities, attributes, and relationships
Three-schema architecture (external, conceptual, internal) and the external level’s role (user views)
DBMS languages/interfaces: DDL vs DML; DDL defines schemas and is stored in the system catalog
DBMS environment modules, including the component that processes DDL into catalog storage
Client-server DBMS architectures: key difference between two-tier and three-tier deployments
ER modeling basics: entities, keys, attributes (incl. composite), and relationship types/constraints
Database design process: building a conceptual schema to capture requirements independent of storage
Advanced ER constraints: ternary relationships, weak entities, identifying relationships, participation
Relational model basics: relations, tuples, attributes; cardinality meaning; tuple ordering is irrelevant
Relational constraints & updates: superkeys, referential integrity, and which updates can violate constraints

About the free online course

Strong database knowledge sits behind nearly every modern application, from e-commerce and finance to mobile apps and analytics. This course helps you understand how Database Management Systems (DBMS) organize data reliably, keep it consistent, and make it accessible to the right people at the right time. If you have ever wondered why databases outperform scattered files and spreadsheets, you will gain the foundational concepts to reason about data as a structured system rather than a collection of documents.

You will start by building clear intuition about what a DBMS is, why organizations use it, and how different types of users interact with a database environment. From there, the course guides you through essential ideas that underpin real-world database solutions, including key characteristics of DBMS technology, the historical evolution of database applications, and the fundamental models used to represent data in ways that match how people think and how software executes.

A major focus is designing databases correctly from the start. You will explore the three-schema architecture to understand how databases separate user views from logical design and physical storage, and how this separation supports change, scalability, and security. You will also learn how DBMS languages and interfaces support both definition and use of data, and how internal DBMS modules translate definitions into catalog structures the system can manage.

As you move into data modeling, you will develop practical understanding of the Entity-Relationship approach, including attributes, keys, and relationships, with attention to common edge cases such as composite attributes, participation constraints, and relationships involving multiple entities. You will then connect these ideas to the relational model, where you will study the behavior of relations, how constraints protect data quality, and why concepts like super keys and referential integrity matter when data changes over time.

Throughout, short exercises reinforce each concept so you can check your understanding and build confidence. By the end, you will be able to discuss DBMS architectures, explain core modeling choices, and anticipate integrity issues that appear during inserts, updates, and deletes—skills that translate directly to more advanced work in SQL, database design, and backend development.

Course content

Video class: Introduction to Database Management Systems 11m
Exercise: What is a key advantage of using a Database Management System (DBMS) over a traditional file system?
Video class: DBMS Characteristics 12m
Exercise: Which of the following is a characteristic that distinguishes a Database Management System (DBMS) from traditional file systems?
Video class: Database Users 10m
Exercise: Which of the following database users are primarily responsible for managing resources and authorizing access to the database?
Video class: Advantages 15m
Exercise: What is one of the main advantages of a Database Management System (DBMS) over traditional file systems?
Video class: History of Database Applications 08m
Exercise: Which of the following statements about the evolution of database management systems is true?
Video class: Fundamentals of Database Systems 06m
Exercise: Which category of data model includes concepts like entities, attributes, and relationships to present data in a way that is closer to how users perceive it?
Video class: Three-Schema Architecture 06m
Exercise: What is the role of the external level in the three schema architecture of a database system?
Video class: DBMS Languages, Interfaces, and Classification 12m
Exercise: What is the primary function of the Data Definition Language (DDL) in database management systems?
Video class: Database System Environment 07m
Exercise: Which module in a Database Management System (DBMS) is responsible for transforming schemas defined by the Data Definition Language (DDL) into a format stored in the catalog?
Video class: DBMS Architecture 08m
Exercise: What is a key difference between the two-tier and three-tier client-server architectures in a DBMS?

Video class: Basic Concepts of Entity-Relationship Model 08m
Exercise: Which of the following is an example of a composite attribute in an entity-relationship model?
Video class: Database Design Process 11m
Exercise: In the database design process, what is the main purpose of creating a conceptual schema?
Video class: Concept of Relationships in ER Diagram 15m
Exercise: What type of relationship exists when there is an association among three entities?
Video class: Exercises based on ER Model Concepts (Part 1) 14m
Exercise: In an Entity-Relationship (ER) diagram for a bank database, which of the following correctly describes the identifying relationship and participation constraints between a 'Bank' entity type and its related 'Bank Branch' weak entity type?
Video class: Exercises based on ER Model Concepts (Part 2) 11m
Exercise: In an Entity-Relationship (ER) diagram, which of the following min-max constraints is correct given that an instructor can teach between two to four courses, and each course may use up to five different textbooks?

Video class: Introduction to Relational Data Model 06m
Exercise: In the context of the relational database model, what does cardinality refer to?
Video class: Characteristics of Relations 07m
Exercise: What is a characteristic of a relational database with regard to the ordering of tuples?
Video class: Relational Model Constraints 12m
Exercise: Which statement accurately describes a characteristic of a super key in the relational database model?
Video class: Update Operations/Dealing with Constraint Violations 09m
Exercise: In a relational database system, which update operation is most likely to cause a violation of the referential integrity constraint?
Video class: Exercises based on Relational Model (Part 1) 12m
Exercise: Which of the following statements about the relational model of databases is correct?
Video class: Exercises based on Relational Model (Part 2) 08m
Exercise: In a relational database with the schemas Student (SSN, Name, Major, BDate), Course (CourseNumber, Quarter, Grade), Enroll (SSN, CourseNumber, Quarter, Grade), Text (BookISBN, BookTitle, Publisher, Order), and BookAdoption (CourseNumber, Quarter, BookISBN), which attribute in the Enroll relation is a foreign key referencing the Student relation?

Video class: Relational Algebra Operations - Unary 15m
Exercise: Which relational algebra operation is used to select or retrieve data from a relation that satisfies a particular condition?
Video class: Relational Algebra Operations - Set Theory 11m
Exercise: Which operation in relational algebra results in a relation that includes all tuples that are in both relations being compared?
Video class: Relational Algebra Operations - Binary 19m
Exercise: What relational algebra operation would you use if you need to find employees who have participated in all workshops available?
Video class: Additional Relational Algebra Operations 21m
Exercise: Which of the following additional relational algebra operations is specifically used to handle information that cannot be joined using attributes with matching values, allowing all tuples to be included regardless of a match?

Video class: Relational Algebra Queries (Part 1) 21m
Exercise: In a database system, which of the following is a key purpose of performing a join operation between two relations?
Video class: Relational Algebra Queries (Part 2) 11m
Exercise: Which relational algebra operation is generally used to retrieve the names of employees who work for departments led by managers that also have dependents?