Database Systems - Module 2: Data Models

Vocabulary flashcards covering data modeling concepts, building blocks, business rules, historical evolution, Big Data technologies, and levels of data abstraction.

Data Modeling

An iterative, progressive process of creating a specific data model for a determined problem domain.

Data Model

A relatively simple representation of more complex real-world data structures.

Entity

A person, place, thing, concept, or event about which data will be collected and stored.

Attribute

A characteristic of an entity.

Relationship

An association among entities, which can be one-to-one (1:1), one-to-many (1:M), or many-to-many (M:N).

Constraint

A restriction placed on data to help ensure data integrity.

Business Rule

A brief, precise, and unambiguous description of a policy, procedure, or principle within a specific organization.

Hierarchical Model

A data model developed in the 1960s to manage large amounts of data for complex manufacturing projects, structured using levels or segments.

Segment

The equivalent of a file system's record type in a hierarchical database structure.

Network Model

A data model created to represent complex data relationships more effectively than the hierarchical model, improve database performance, and impose a database standard.

Schema

The conceptual organization of the entire database as viewed by the database administrator.

Subschema

The portion of the database defined for application programs that produce desired information from database data.

Data Manipulation Language (DML)

A language that defines the environment in which data can be managed and is used to work with data in the database.

Data Definition Language (DDL)

A schema language that enables the database administrator to define schema components.

Relation

A two-dimensional structure composed of intersecting rows and columns in the relational data model.

Tuple

A row within a relation in the relational data model.

Relational Database Management System (RDBMS)

A sophisticated system that manages relational database details while presenting data to end users as a collection of tables.

Entity Relationship Model (ERM)

A graphical data model that uses entity relationship diagrams (ERD) to picture entities and their relationships.

Entity Type

A collection of entities that often corresponds to a table in a relational database.

Entity Instance

A specific person, place, object, event, or concept that often corresponds to a row in a table.

Object-Oriented Data Model (OODM)

A semantic data model where both data and its relationships are contained in a single structure known as an object.

Class

A collection of similar objects with shared structure and behavior in an object-oriented data model.

Method

A real-world action defined within a class, such as finding, changing, or printing object details.

Inheritance

The ability of an object within a class hierarchy to inherit attributes and methods from classes above it.

Extended Relational Data Model (ERDM)

A model that integrates object-oriented features within the simpler relational database structure.

Extensible Markup Language (XML)

A standard used for the efficient and effective exchange of structured, semistructured, and unstructured data.

Internet of Things (IoT)

A web of Internet-connected devices exchanging and collecting data.

Big Data

A movement focused on finding new and better ways to manage massive web- and sensor-generated data to derive business insight.

3 Vs

The three basic characteristics of Big Data databases: volume, velocity, and variety.

Hadoop

A Java-based, open-source, high-speed, fault-tolerant distributed storage and computational framework.

Hadoop Distributed File System (HDFS)

A highly distributed, fault-tolerant file storage system designed to manage large amounts of data at high speeds.

MapReduce

An open-source application programming interface (API) that provides fast data analytics services.

NoSQL

A large-scale distributed database system designed for performance and handling structured and unstructured data without relying on the relational model or SQL.

External Model

The end users' view of the data environment, represented by external schemas for specific business units.

Conceptual Model

A global, software- and hardware-independent view of the entire database as understood by the entire organization.

Internal Model

The representation of a database as seen by the DBMS, which is software dependent but hardware independent.

Physical Model

The lowest level of data abstraction that describes how data is saved on storage media, making it both software and hardware dependent.

Logical Independence

The capability to change the internal model without affecting the conceptual model.

Physical Independence

The capability to change the physical model without affecting the internal model.