Database Systems: Design, Implementation, and Management (Chapters 1–6)

Comprehensive vocabulary practice flashcards covering fundamental and advanced database concepts, data models, relational database theory, entity relationship modeling, extended ER modeling, and table normalization from Chapters 1 through 6.

Data

Raw facts, such as a telephone number, a birth date, a customer name, or a year-to-date sales value, that have little meaning unless organized in some logical manner.

Information

The result of processing raw data to reveal its meaning, requiring context to reveal that meaning.

Metadata

Data about data, providing descriptions of data characteristics and relationships within the data.

Database Management System (DBMS)

A collection of programs that manages the database structure and controls access to the data stored in the database.

Data Inconsistency

A condition in which different and conflicting versions of the same data appear in different places.

Ad Hoc Query

A spur-of-the-moment question issued to a DBMS for data manipulation or retrieval.

Operational Database

A database designed primarily to support a company's day-to-day operations; also known as a transactional or production database.

Analytical Database

A database that focuses primarily on storing historical data and business metrics used exclusively for tactical or strategic decision making.

Online Analytical Processing (OLAP)

A set of tools that work together to provide an advanced data analysis environment for retrieving, processing, and modeling data from a data warehouse.

NoSQL

A new generation of database management systems that is not based on the traditional relational model, designed to handle unprecedented data volume, variety, and velocity.

Structural Dependence

A file system characteristic where access to a file is dependent on its own internal file structure, requiring program code changes if the file structure changes.

Data Independence

A condition in which changes in data storage characteristics do not affect data access or require modifications to application programs.

Data Redundancy

A condition in which the same data is stored unnecessarily in multiple places across an organization.

Data Model

A relatively simple representation, often graphical, of complex real-world data structures and problem domains.

Entity

A person, place, thing, concept, or event in the real-world environment about which data are to be collected and stored.

Attribute

A characteristic or property of an entity.

Constraint

A restriction placed on the data to ensure data integrity.

Business Rules

Precise, written descriptions of policies, procedures, or principles within a specific organization that define the characteristics and operational actions of data.

Segment

In the hierarchical data model, the equivalent of a file system's record type arranged in an upside-down tree structure.

Hadoop Distributed File System (HDFS)

A highly distributed, fault-tolerant file storage system that uses a write-once, read-many model across clusters of computers using name nodes, data nodes, and client nodes.

MapReduce

An open-source API that distributes data analytics processing across thousands of nodes in parallel using a Map function to divide jobs and a Reduce function to integrate results.

Eventual Consistency

A data consistency model in distributed NoSQL databases where updates propagate across the system over time until all data copies eventually match.

External Model

The end users' view of the data environment, represented by external schemas that are independent of both hardware and software.

Conceptual Model

A global, integrated view of the entire database representing all external views, designed to be independent of both hardware and DBMS software.

Internal Model

The representation of a database as seen by the DBMS, mapping the conceptual model to specific database software while remaining hardware-independent.

Physical Model

The lowest level of data abstraction that describes physical storage media and data access methods, dependent on both hardware and software.

Tuple

A single row within a relational table representing an entity occurrence in an entity set.

Attribute Domain

The specific range or set of allowable values defined for a particular column in a table.

Superkey

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

Candidate Key

A minimal, irreducible superkey that does not contain a subset of attributes that is itself a superkey.

Primary Key

A candidate key selected to uniquely identify all other attribute values in any given row, which cannot contain null entries.

Foreign Key (FK)

An attribute or combination of attributes in one table whose values must either match the primary key in another table or be null.

Secondary Key

An attribute or combination of attributes used strictly for data retrieval purposes.

Entity Integrity

The integrity rule requiring that all primary key entries be unique and that no part of a primary key may contain a null value.

Referential Integrity

The integrity rule requiring that every non-null foreign key value reference an existing valid primary key value in the related table.

Flag

A special code or dummy variable implemented to indicate the absence of a value, prevent nulls, or trigger a required response.

Natural Join

A relational algebra operation that links tables by selecting rows with common values in common attributes through a sequence of PRODUCT, SELECT, and PROJECT operations.

Left Outer Join

A relational operator that yields all rows from the left table, including those without matching values in the right table, filling unmatched right-side attributes with nulls.

Right Outer Join

A relational operator that yields all rows from the right table, including those without matching values in the left table, filling unmatched left-side attributes with nulls.

Divide

A relational algebra operator that outputs rows from a table associated with all the values found in a single-column table.

Data Dictionary

A system storage repository that provides a detailed accounting of all tables, attribute names, data types, formats, and metadata in a database.

System Catalog

A detailed system-level data dictionary that describes all objects (such as tables, views, indexes, and user accounts) within the database.

Unique Index

An index structure in which each index key can have only one pointer value (row) associated with it.

Rule Zero

Dr. E.F. Codd's foundational relational rule stating that to be considered relational, a database must use its relational facilities exclusively for management.

Required Attribute

An attribute that must have a value and cannot be left empty (null).

Optional Attribute

An attribute that does not require a value and may be left blank.

Composite Identifier

A primary key identifier composed of more than one attribute.

Composite Attribute

An attribute that can be subdivided into smaller components, such as ADDRESS into street, city, state, and zip code.

Simple Attribute

An attribute that cannot be subdivided into smaller components, such as age or sex.

Multivalued Attribute

An attribute that can have multiple values for a single entity occurrence, such as multiple colors for a car.

Derived Attribute

An attribute whose value is not physically stored in the database but is calculated from other stored attributes using an algorithm.

Connectivity

The classification label used to describe the relationship type between entities (such as 1:1, 1:M, or M:N).

Cardinality

A property that expresses the minimum and maximum number of entity occurrences associated with one occurrence of a related entity.

Weak (Non-Identifying) Relationship

A relationship in which the primary key of the related entity does not contain the primary key component of the parent entity.

Strong (Identifying) Relationship

A relationship that exists when the primary key of the related entity contains the primary key component of the parent entity.

Weak Entity

An entity that is existence-dependent on another entity and whose primary key is partially or totally derived from its parent entity.

Unary Relationship

A relationship that exists when an association is maintained within occurrences of a single entity set; also known as a recursive relationship.

Ternary Relationship

An association that involves three distinct entities simultaneously.

Associative Entity

A bridge or composite entity used to implement an M:N relationship, composed of the primary keys of the entities to be linked as foreign keys.

Extended Entity Relationship (EER) Model

The data model resulting from adding advanced semantic constructs, such as supertypes, subtypes, and clusters, to the original entity relationship model.

Entity Supertype

A generic entity type that contains common characteristics and attributes shared by one or more entity subtypes.

Entity Subtype

A specialized entity type that inherits attributes from an entity supertype and contains its own unique characteristics.

Specialization Hierarchy

A structural arrangement depicting higher-level supertypes and lower-level subtypes connected by 'IS-A' relationships.

Subtype Discriminator

An attribute in an entity supertype that determines to which entity subtype each supertype occurrence is related.

Disjoint Subtypes

Nonoverlapping subtypes containing unique subsets of a supertype, meaning an instance can belong to only one subtype, denoted by a 'd' in the category symbol.

Overlapping Subtypes

Subtypes containing nonunique subsets of a supertype, allowing a single supertype occurrence to simultaneously belong to multiple subtypes, denoted by an 'o'.

Partial Completeness

A specialization hierarchy constraint symbolized by a circle over a single line, indicating that some supertype occurrences do not belong to any subtype.

Total Completeness

A specialization hierarchy constraint symbolized by a circle over a double line, indicating that every supertype occurrence must belong to at least one subtype.

Specialization

The top-down process of identifying more specific entity subtypes from a higher-level entity supertype based on grouping unique characteristics.

Generalization

The bottom-up process of identifying a generic entity supertype from multiple lower-level entity subtypes based on grouping shared characteristics.

Entity Cluster

A virtual entity type used in an ERD to represent multiple interrelated entities and relationships, simplifying cluttered diagrams.

Natural Key

A real-world identifier familiar to end users and part of day-to-day business vocabulary, used to identify entity instances.

Surrogate Key

An artificial, system-assigned primary key created when no suitable natural key exists or the candidate key is too long or cumbersome.

Time-Variant Data

Data whose values change over time and for which a historical record of values and change dates must be retained.

Fan Trap

A design trap occurring when one entity is in two simultaneous 1:M relationships to other entities, creating an association between those other entities that is not accurately represented.

Redundant Relationship

A condition in an ERD where multiple relationship paths exist between related entities, introducing potential inconsistencies.

Normalization

A process for evaluating and correcting table structures to minimize data redundancies and eliminate data anomalies.

Functional Dependence

A state in which attribute $B$ is dependent on attribute $A$ ($A \rightarrow B$) if each value of $A$ determines one and only one value of $B$.

Determinant

Any attribute whose value determines other values within a row; the attribute on the left side of a functional dependency arrow ($A$ in $A \rightarrow B$).

Fully Functional Dependence

A condition where attribute $B$ is functionally dependent on a composite key $A$, but not on any subset of that composite key.

Partial Dependency

A functional dependency in which a nonkey attribute is dependent on only a portion of a composite primary key.

Transitive Dependency

A dependency that exists when a nonkey attribute determines another nonkey attribute ($X \rightarrow Y$ and $Y \rightarrow Z$, where $X$ is the primary key).

Repeating Group

A group of multiple entries of the same type that can exist for any single key attribute occurrence in an unnormalized record.

First Normal Form (1NF)

A table format characterized by defined primary keys, no repeating groups, and all attributes being functionally dependent on the primary key.

Second Normal Form (2NF)

The state of a table that is in 1NF and contains no partial dependencies, meaning no nonkey attribute depends on a subset of the primary key.

Third Normal Form (3NF)

The state of a table that is in 2NF and contains no transitive dependencies, meaning no nonkey attribute determines another nonkey attribute.

Boyce-Codd Normal Form (BCNF)

A special, stricter case of 3NF in which every determinant in the table is a candidate key.

Fourth Normal Form (4NF)

The state of a table that is in 3NF (or BCNF) and contains no multiple sets of independent multivalued dependencies.

Fifth Normal Form (5NF / PJNF)

Project-join normal form; the state of a table in 4NF that cannot undergo further lossless decomposition into smaller tables without losing data.

Denormalization

The deliberate process of converting higher normal form tables into lower normal forms to reduce join operations and increase processing speed at the expense of data redundancy.

Minimal Data Rule

A core data modeling principle stating that 'all that is needed is there, and all that is there is needed.'