Week 7: Advanced Data Modeling

These flashcards cover key vocabulary and concepts related to advanced data modeling techniques and principles as outlined in the provided lecture notes.

Extended Entity Relationship Model (EERM)

A model that adds more semantic constructs to the original entity relationship (ER) model.

Entity Supertype

A generic entity type related to one or more entity subtypes, containing common characteristics.

Entity Subtype

Contains unique characteristics of each entity subtype.

Specialization Hierarchy

Depicts the arrangement of higher-level entity supertypes and lower-level entity subtypes, illustrating relationships in terms of 'is-a'.

Subtype Discriminator

An attribute in the supertype entity that determines the related entity subtype.

Disjoint Subtypes

Contain a unique subset of the supertype entity set and are known as nonoverlapping subtypes.

Overlapping Subtypes

Contain nonunique subsets of the supertype entity set, where instances can belong to multiple subtypes.

Primary Key

A single attribute or a combination of attributes that uniquely identifies each entity instance.

Natural Key

A real-world identifier used to uniquely identify real-world objects.

Composite Primary Key

A primary key that consists of two or more attributes to uniquely identify an entity instance, often used for bridge or weak entities.

Surrogate Primary Key

A primary key created by the database designer to simplify the identification of entity instances, often generated by the DBMS.

Time-Variant Data

Data whose values change over time and for which a history of changes must be retained.

Fan Trap

A design trap that occurs when one entity is involved in multiple relationships, leading to associations not accurately expressed in the model.

Redundant Relationships

Multiple relationship paths between related entities that can complicate the design.

Completeness Constraint

Specifies whether every supertype occurrence must also be a member of at least one subtype.