DBMS Terms and Definitions

Table

A structured set of data organized in rows and columns within a database. Each table represents a specific entity and its attributes.

metadata

Data that describes other data, providing information about a database's structure, relationships, and constraints.

database

A collection of organized data that can be easily accessed, managed, and updated. It serves as a structured repository for storing and retrieving information.

records

Individual entries in a table that contain data related to a specific entity, represented by rows.

columns / fields

Vertical divisions in a table that define the type of data stored, represented by headers.

attributes

Characteristics or properties of a record that provide specific details about the entity.

relational database

A type of database that stores data in tables with predefined relationships between them, allowing for efficient data retrieval and management.

conceptual data model

A representation of the data structures and relationships in a database, focusing on how data is organized and interrelated without detailing the physical implementation.

logical data model

A representation of data that defines the structure of the data elements and their relationships, independent of physical considerations.

physical data model

A detailed representation of the data structures and storage mechanisms in a database, specifying how data is stored on physical media and how it interacts with the hardware.

primary key

A unique identifier for a record in a database table, ensuring that each entry can be uniquely distinguished from others.

foreign key

A field in a database table that creates a link between two tables by referencing the primary key of another table, ensuring referential integrity.

surrogate

A surrogate key is a unique identifier for an entity in a database that is not derived from application data, often used to simplify relationships between tables.

schema

A blueprint or structure that defines how data is organized in a database, including tables, fields, relationships, and constraints.

entity

An object or concept that is represented in a database, typically corresponding to a table, which contains attributes or properties.

ERD - Entity Relationship Diagram

A visual representation of the entities in a database and their relationships, often used in the design phase of database development.

composite key

A combination of two or more columns in a database table that uniquely identifies a row within that table.

data type

The classification of data based on the type of value it can hold, such as integer, string, or date, which determines how the data is stored and manipulated in a database.

RDMS - Relational Database Management System

A type of database management system that stores data in a structured format using rows and columns, allowing for relationships between tables.

syntax error

An error in the code that violates the rules of the programming language's syntax, preventing the code from being executed.

Query

A request for data or information from a database, typically written in a specific language such as SQL.

Statement

A command or instruction in SQL that performs a specific action, such as retrieving or modifying data in a database.

Clause

A component of a SQL statement that specifies a condition or action, such as SELECT, WHERE, or ORDER BY.

Keyword

A reserved word in SQL that has a specific meaning and is used to perform operations such as defining, manipulating, or querying data within a database.

cardinality / relationships

The number of elements in one set that are related to the number of elements in another set, often used to describe the nature of relationships between tables in a database.

third normal form

A database normalization form that eliminates transitive dependencies, ensuring that all non-key attributes are fully functionally dependent on the primary key. \

class

A blueprint for creating objects in object-oriented programming, defining properties and methods.

CRUD - PG74

An acronym for Create, Read, Update, and Delete, which represents the four basic operations for managing data in a database.

Index

A database structure that improves the speed of data retrieval operations on a database table at the cost of additional space and maintenance overhead.

View

A virtual table in a database that provides a way to present data from one or more tables in a specific format, allowing users to simplify complex queries and enhance security.

Integrity Constraints

Rules that ensure data accuracy and consistency in a database, preventing invalid data entry.

Intersection table

A table used to represent a many-to-many relationship between two other tables by storing foreign keys from both tables.

select

A SQL statement used to query and retrieve data from a database.

from

a SQL clause used to specify the table from which to retrieve data.

where

a SQL clause used to specify conditions for filtering records in a query.

join types

Different methods to combine rows from two or more tables based on related columns.

recursive relationship

A type of relationship in a database where an entity is related to itself, often used to represent hierarchical data.