Module 2 - Database Overview

Data

Raw facts that have not yet been organized to reveal meaning.

Information

Results from processing raw data to reveal meaning; it requires context and should be accurate, relevant, and timely.

Field

A character or group of characters that has a specific meaning and is used to define and store data.

Record

A logically connected set of one or more fields that describes a person, place, or thing.

File

A collection of related records.

File-based system

A system that relies primarily on text-based files to run the system.

Database

A shared, integrated computer structure that stores data.

Metadata

Data about data that describes data characteristics and relationships.

DBMS (Database Management System)

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

Data redundancy

When the same data is stored unnecessarily in different places. It can cause poor security, data inconsistency, data-entry errors, and data integrity problems.

Data anomaly

Occurs when not all required changes in redundant data are made successfully.

Update anomaly

Occurs when a change to redundant data is made in one place but is not made in other places.

Deletion anomaly

Occurs when deleting data unintentionally causes other needed data to be deleted.

Insertion anomaly

Occurs when adding new data requires unnecessary or dummy data to also be added.

Structural dependence

Access to a file depends on its structure, so programs must be modified when the file structure changes.

Structural independence

File structure can be changed without affecting the application's ability to access the data.

Data dependence

Data access changes when data storage characteristics change, such as attribute type or size.

Data independence

Data storage characteristics can be changed without affecting the program's ability to access the data.

Single-user database

A database that supports one user at a time.

Multiuser database

A database that supports multiple users at the same time.

Workgroup database

A database that supports a small number of users or a single department.

Enterprise database

A database that supports many users across many departments.

Centralized database

A database that holds data at a single site.

Distributed database

A database that distributes the database across different sites.

Cloud database

A database created and maintained using cloud data services.

General-purpose database

A database that holds a wide variety of data used in multiple disciplines.

Discipline-specific database

A database focused on a specific subject area.

Operational database

A database designed to support an organization's daily operations.

Data warehouse

A database that holds data in a format optimized for decision support.

OLAP (Online Analytical Processing)

Tools used to retrieve, process, and model data within a data warehouse.

Business intelligence

Captures and processes business data to generate information that supports decision making.

Unstructured data

Data that exists in its original, raw state.

Structured data

Data that results from formatting, with structure applied based on the type of processing to be performed.

Semistructured data

Data that has been processed to some extent.

SQL (Structured Query Language)

The standard query language supported by most DBMS vendors.

Query language

Lets the user specify what must be done without having to specify how.

Database system environment

The components that define and regulate the collection, storage, management, and use of data in a database environment.

Five components of a database system environment

Hardware, software, people, procedures, and data.

Data dictionary

Stores definitions of data elements and their relationships.

Security management

Enforces user security and data privacy.

Backup and recovery management

Enables recovery of the database after a failure.

Data integrity management

Minimizes redundancy and maximizes consistency.

Multiuser access control

Allows multiple users to access a database concurrently without compromising its integrity.

Database design

Activities focused on designing the database structure used to store and manage end-user data.

Generative AI

AI systems trained on input data that generate new data based on what was learned from the original data.

Machine learning

Uses statistical techniques to identify patterns, dependencies, relationships, and trends to forecast future trends.

AI challenges

Ethical and data privacy issues, inherited bias, and resource utilization.