ICT 2ND QUARTER

Centralized Database

stores and maintains all data in a single point or location

Distributed Database

spreads data storage and processing across multiple systems

Decentralized Database

allows each area to manage its own data while still being accessible

Blockchain Database

an example of decentralized architecture where data is stored in chained blocks

Nodes

individual servers or computers that store parts of a distributed database

Facebook Database Type

uses distributed database architecture for speed and reliability

Server

main computer that manages resources, data, and security in a client-server system

Client

a device that connects to a server and requests data or services

Cloud Database

data accessed and managed through the Internet

DBaaS (Database as a Service)

another term for cloud database architecture

Data Redundancy

duplication of data; reduced through proper database architecture

Hardware Cost

one disadvantage of database architecture due to expensive setup requirements

Tier

a group of systems that share the same properties and rules

1Tier Architecture

both client and server are on the same machine

Simplest Architecture

1tier; fastest because it avoids network delays

MS Office Example

a 1tier architecture application

1Tier Limitation

cannot share information between clients

2Tier Architecture

client and server communicate through TCP/IP

Client Role

sends requests and instructions to the server

Server Role

stores, manages, and processes data

2Tier Disadvantage

clients must reinstall the application when updates occur

3Tier Architecture

separates user, application, and database layers

3Tier Advantage

provides program-data independence and better maintenance

Web Applications

commonly use 3tier architecture

NTier Architecture

system with multiple layers beyond three

First Database Wave

occurred between 1960-1999; early file systems

Relational Wave

began around 1970; introduced relational databases (SQL-based)

Decision Support Wave

introduced OLAP (Online Analytical Processing) for analysis

Graph Wave

began around 2010; focused on relationships between data points

NoSQL Wave

started around 2008; designed for scalability and unstructured data

Flat File Database

stores data in a single plain text file

Flat File Limitation

inefficient with large volumes of data

Hierarchical Model

arranges data in a tree-like structure

Child Table Rule

each child table has only one parent

Network Model

allows many-to-many relationships between data sets

Record in Network Model

can belong to multiple sets

Relational Model

invented by E

F

Codd; uses tables to represent data

First SQL Implementation

offered commercially by IBM

Rows

also called records in relational databases

Columns

represent attributes or data fields

Primary Key

uniquely identifies each record in a table

Foreign Key

establishes a relationship between two tables

Composite Key

made up of multiple columns used together for identification

Index

improves search and retrieval speed in a database

Relational Model Structure

represents data in rows and columns

Object-Oriented Database

designed to work with objects and classes

OODB Languages

commonly used with Java and Python

Object-Relational Model

combines features of relational and object-oriented databases

Data Warehouse

used mainly for reporting and analytical purposes

Fact Table

stores transactional or measurable data in a data warehouse

SQL (Structured Query Language)

used to create, modify, and query data in databases