Database Management Systems: ER-to-Relational Mapping

Flashcards covering key concepts and terms from the ER-to-Relational Mapping process in database management.

ER-to-Relational Mapping Algorithm

A systematic process for converting an Entity-Relationship model to a relational database schema.

Regular Entity Types

Basic entities that have their own attributes and can exist independently.

Weak Entity Types

Entities that do not have sufficient attributes to form a primary key and depend on a strong entity.

Binary 1:1 Relationship Type

A relationship type where one entity of one type is associated with one entity of another type.

Binary 1:N Relationship Type

A relationship type where one entity of one type is associated with multiple entities of another type.

Binary M:N Relationship Type

A relationship type where multiple entities of one type can be associated with multiple entities of another type.

Multivalued Attributes

Attributes that can have multiple values for a single entity.

N-ary Relationship Types

Relationships that involve more than two entity types.

Preserve Information

Maintain all data attributes during the mapping process.

Constraints

Rules that maintain the integrity and correctness of the database.

Primary Key

A unique identifier for records in a relational database.

Foreign Key

An attribute that creates a link between two tables in a relational database.

Specialization

The process of defining a set of sub-entities from a higher-level entity.

Generalization

The process of defining a higher-level entity that generalizes multiple lower-level entities.

Surrogate Key

An artificially created key used to uniquely identify records not derived from business data.

Mapping of Regular Entity Types

First step in ER-to-relational mapping that creates relations for regular entities.

Mapping of Weak Entity Types

Second step which involves creating relations for weak entities and including foreign keys.

Mapping of Binary 1:1 Relationships

Step to identify participating relations and form appropriate mappings.

Mapping of Binary 1:N Relationships

Mapping where primary keys of N-side entities are included as foreign keys.

Mapping of Binary M:N Relationships

Creating a new relation for M:N relationships to represent connections.

Mapping of Multivalued Attributes

Creating a new relation for each multivalued attribute along with its corresponding keys.

Mapping of N-ary Relationship Types

Creating a new relation that represents n-ary relationships along with keys.

Mapping Specialization or Generalization

Converting specialized or generalized entities into relational schemas.

Multiple Inheritance

When a subclass inherits from multiple parent classes.

Options for Mapping Specialization

Different strategies to represent subclasses in the relational schema.

Single Relation with Type Attribute

A method where a single relation includes a type attribute to distinguish subclasses.

Multiple Relations with Subclass Relationships

Creating distinct relations for subclasses, each with the attributes of their superclass.

Mapping of Union Types

Creating relations for categories with differing keys using surrogate keys.

Category Relation

A relation created to capture the attributes and keys of a category.

Mapping Constraints

The rules and regulations followed during the mapping process.

Dependent Relation

A relation created from weak entity types that relies on strong entity types.

Composite Key

A primary key made up of multiple attributes to uniquely identify a record.

EER Model Constructs

Enhanced Entity-Relationship models that provide additional semantics.

Relational Schema

The blueprint of how a database is constructed, including tables and relationships.

Relationship Relation

A relation created specifically to handle many-to-many relationships between entities.

Cross-reference Relation

A relation set up to cross-reference primary keys of two or more relations.

Unique Identifier

A value that distinctly identifies a record in a relational database.

Attribute

A characteristic or property of an entity.

Primary Key Attribute

The attribute in a relation that uniquely identifies each tuple.