Practice Exam

Enterprise resource planning (ERP)

A business management system that integrates all functions of the enterprise, such as manufacturing, sales, finance, marketing, inventory, accounting, and human resources. ERP systems are software applications that provide the data necessary for the enterprise to examine and manage its activities.

Data warehouse

An integrated decision support database whose content is derived from the various operational databases.

Database application

An application program (or set of related programs) that is used to perform a series of database activities (create, read, update, and delete) on behalf of database users.

Data independence

The separation of data descriptions from the application programs that use the data.

Data modeling and design tools

Software tools that provide automated support for creating data models.

Repository

A centralized knowledge base of all data definitions, data relationships, screen and report formats, and other system components.

Enterprise data modeling

The first step in database development, in which the scope and general contents of organizational databases are specified.

Conceptual schema

A detailed, technology-independent specification of the overall structure of organizational data.

Physical schema

Specifications for how data from a logical schema are stored in a computer's secondary memory by a database management system.

Prototyping

An iterative process of systems development in which requirements are converted to a working system that is continually revised through close work between analysts and users.

Project

A planned undertaking of related activities to reach an objective that has a beginning and an end.

Database

An organized collection of logically related data.

structured data

Stored representations of meaningful objects and event: numbers, text, dates

unstructured data

Stored Representation of meaningful objects and events: images, video, documents.

Data

Stored representations of objects and events that have meaning and importance in the user's environment.

Information

Data that have been processed in such a way as to increase the knowledge of the person who uses the data.

Metadata

Data that describe the properties or characteristics of end-user data and the context of those data.

Data models

Graphical systems used to capture the nature and relationships among data.

Entity

A person, a place, an object, an event, or a concept in the user environment about which the organization wishes to maintain data.

Relational database

A database that represents data as a collection of tables in which all data relationships are represented by common values in related tables.

Database management system (DBMS)

A software system that is used to create, maintain, and provide controlled access to user databases.

User View

A logical description of some portion of the database that is required by a user to perform some task.

Constraint

A rule that cannot be violated by database users.

Systems development life cycle (SDLC)

The traditional methodology used to develop, maintain, and replace information systems.

Logical schema

The representation of a database for a particular data management technology.

Agile software development

An approach to database and software development that emphasizes "individuals and interactions over processes and tools, working software over comprehensive documentation, customer collaboration over contract negotiation, and response to change over following a plan."

Data lake

A large integrated repository for internal and external data that does not follow a predefined schema.

Relation

A named, two-dimensional table of data.

Primary key

An attribute or a combination of attributes that uniquely identifies each row in a relation.

Composite key

A primary key that consists of more than one attribute.

Foreign key

An attribute in a relation that serves as the primary key of another relation in the same database.

Null

A value that may be assigned to an attribute when no other value applies or when the applicable value is unknown.

Entity integrity rule

A rule that states that no primary key attribute (or component of a primary key attribute) may be null.

Referential integrity constraint

A rule that states that either each foreign key value must match a primary key value in another relation or the foreign key value must be null.

Well-structured relation

A relation that contains minimal redundancy and allows users to insert, modify, and delete the rows in a table without errors or inconsistencies.

Anomaly

An error or inconsistency that may result when a user attempts to update a table that contains redundant data. The three types of anomalies are insertion, deletion, and modification anomalies.

Recursive foreign key

A foreign key in a relation that references the primary key values of the same relation.

Normalization

The process of decomposing relations with anomalies to produce smaller, well-structured relations.

Normal form

A state of a relation that requires that certain rules regarding relationships between attributes (or functional dependencies) are satisfied.

Functional dependency

A constraint between two attributes in which the value of one attribute is determined by the value of another attribute.

Determinant

The attribute on the left side of the arrow in a functional dependency.

Candidate key

An attribute, or combination of attributes, that uniquely identifies a row in a relation.

First normal form (1NF)

A relation that has a primary key and in which there are no repeating groups.

Second normal form (2NF)

A relation in first normal form in which every nonkey attribute is fully functionally dependent on the primary key.

Partial functional dependency

A functional dependency in which one or more nonkey attributes are functionally dependent on part (but not all) of the primary key.

Third normal form (3NF)

A relation that is in second normal form and has no transitive dependencies.

Transitive dependency

A functional dependency between the primary key and one or more nonkey attributes that are dependent on the primary key via another nonkey attribute.

Synonyms

Two (or more) attributes that have different names but the same meaning.

Alias

An alternative name used for an attribute.

Homonym

An attribute that may have more than one meaning.

Enterprise key

A primary key whose value is unique across all relations.

Data integrity

Mechanisms for implementing business rules that maintain integrity of manipulated data

Domain Constraints

Allowable values for an attribute (includes data types and restrictions on values)

Insertion Anomaly

adding new rows forces user to create duplicate data

Deletion Anomaly

deleting rows may cause a loss of data that would be needed for other future rows

Modification Anomaly

changing data in a row forces changes to other rows because of duplication

Surrogate Primary Key

A serial number or other system-assigned primary key for a relation.

Enhanced entity-relationship (EER) model

A model that has resulted from extending the original E-R model with new modeling constructs.

Subtype

A subgrouping of the entities in an entity type that is meaningful to the organization and that shares common attributes or relationships distinct from other subgroupings.

Supertype

A generic entity type that has a relationship with one or more subtypes.

Attribute inheritance

A property by which subtype entities inherit values of all attributes and instances of all relationships of their supertype.

Generalization

The process of defining a more general entity type from a set of more specialized entity types.

Specialization

The process of defining one or more subtypes of the supertype and forming supertype/subtype relationships.

Completeness constraint

A type of constraint that addresses whether an instance of a supertype must also be a member of at least one subtype.

Total specialization rule

A rule that specifies that each entity instance of a supertype must be a member of some subtype in the relationship.

Partial specialization rule

A rule that specifies that an entity instance of a supertype is allowed not to belong to any subtype.

Disjointness constraint

A constraint that addresses whether an instance of a supertype may simultaneously be a member of two (or more) subtypes.

Disjoint rule

A rule that specifies that an instance of a supertype may not simultaneously be a member of two (or more) subtypes.

Overlap rule

A rule that specifies that an instance of a supertype may simultaneously be a member of two (or more) subtypes.

Subtype discriminator

An attribute of a supertype whose values determine the target subtype or subtypes.

Supertype/subtype hierarchy

A hierarchical arrangement of supertypes and subtypes in which each subtype has only one supertype.

Entity cluster

A set of one or more entity types and associated relationships grouped into a single abstract entity type.

Universal data model

A generic or template data model that can be reused as a starting point for a data modeling project.

business rule

A statement that defines or constrains some aspect of the business. It is intended to assert business structure or to control or influence the behavior of the business.

Term

A word or phrase that has a specific meaning for the business.

Fact

An association between two or more terms.

Entity type

A collection of entities that share common properties or characteristics.

Entity instance

A single occurrence of an entity type.

Strong entity type

An entity that exists independently of other entity types.

Weak entity type

An entity type whose existence depends on some other entity type.

Identifying owner

The entity type on which the weak entity type depends.

Identifying relationship

The relationship between a weak entity type and its owner.

Attribute

A property or characteristic of an entity or relationship type that is of interest to the organization.

Required attribute

An attribute that must have a value for every entity (or relationship) instance with which it is associated.

Optional attribute

An attribute that may not have a value for every entity (or relationship) instance with which it is associated.

Composite attribute

An attribute that has meaningful component parts (attributes).

Simple (or atomic) attribute

An attribute that cannot be broken down into smaller components that are meaningful to the organization.

Multivalued attribute

An attribute that may take on more than one value for a given entity (or relationship) instance.

Derived attribute

An attribute whose values can be calculated from related attribute values.

Identifier

An attribute (or combination of attributes) whose value distinguishes instances of an entity type.

Composite identifier

An identifier that consists of a composite attribute.

Relationship type

A meaningful association between (or among) entity types.

Relationship instance

An association between (or among) entity instances where each relationship instance associates exactly one entity instance from each participating entity type.

Associative entity

An entity type that associates the instances of one or more entity types and contains attributes that are peculiar to the relationship between those entity instances.

Degree

The number of entity types that participate in a relationship.

Unary relationship

A relationship between instances of a single entity type.

Binary relationship

A relationship between the instances of two entity types.

Ternary relationship

A simultaneous relationship among the instances of three entity types.

Cardinality constraint

A rule that specifies the number of instances of one entity that can (or must) be associated with each instance of another entity.

Minimum cardinality

The minimum number of instances of one entity that may be associated with each instance of another entity.