DBMS and Relational Model Vocabulary

This flashcard set covers the fundamental concepts of Database Management Systems, including relational model basics, integrity constraints, ER concepts, and the pros and cons of using a DBMS.

Tuple

A row in a table.

Attribute

A column in a table.

Relation

A table in a database.

Cardinality

Number of tuples (rows) in a relation.

Degree

Number of attributes (columns).

Null

A value that is unknown or missing. Not zero or blank.

Relational Database

A collection of normalized relations with unique names.

DBMS

Software used to store and manage data in tables.

Functional Dependency

A dependency between attributes.

Normalization

Process of reducing redundancy and avoiding anomalies.

Primary Key

A unique identifier for each row used to avoid duplicate data.

Foreign Key

A key that links tables together.

Composite Key/Constraint

A key made of more than one attribute.

Entity Integrity

Each row in a table must be unique.

Referential Integrity

Foreign key must match a candidate/primary key or be NULL.

Domain Constraint

A set of allowable values for an attribute.

CHECK

The keyword used for Domain Constraint.

Entity Type

A person, object, concept, or process.

Entity Occurrence

A specific instance of an entity type.

Relationship

A meaningful association between entity types.

One-to-One ($1:1$)

One entity relates to only one entity (e.g., One person $\rightarrow$ one passport).

One-to-Many ($1:N$)

One entity relates to many entities (e.g., One teacher $\rightarrow$ many students).

Many-to-Many ($N:N$)

Many entities relate to many entities (e.g., Students $\rightleftharpoons$ courses).

Benefits of Normalization

Minimum redundancy, Avoid anomalies, and Validate ERD.

Control of data redundancy

DBMS advantage that reduces duplicate data.

Data consistency

DBMS advantage that keeps data accurate and uniform.

Sharing of data

DBMS advantage where multiple users can access data.

Improved security

DBMS advantage that protects data from unauthorized access.

Improved backup and recovery

DBMS advantage that helps restore lost data.

Disadvantages of DBMS

Complexity, large size, high cost, hardware cost, conversion cost, performance issues, and high failure impact.