DATABASE MODULE 5

Database Architecture

overall design and structure of a database system, including the hardware and software components.

The Physical Layer

lowest level of the architecture, consists of the hardware and operating system that the database runs on, server, storage devices, network infrastructure.

The Logical Layer

Middle level, consists of the database management system (DBMS) software and database itself.

The View Layer

Highest Level, consists of the user interfaces and application programming interfaces (APIs).

Data Model

Defines structure and relationships of the data stored in database.

client-server architecture

runs on a central server and clients connect to access and manipulate the data.

peer-to-peer architecture

each node has a copy of the database, can act as both a client and a server.

Relational model (RM)

most widely used model, based on the concept of tables. well suited for large and complex data.

Hierarchical model (HM)

based on the structure of a tree, best suited for applications where the data has a clear parent-child relationship. best suited for data has a clear parent-child relationship.

Network model (NM)

similar to the hierarchical model, but it allows for multiple parent-child relationships. best suited for data has many-to-many relationships.

Object-oriented model (OOM)

based on the concept of objects and classes, used in object-oriented programming languages. Best suited for data represents real-world objects and their relationships.

Document model (DM)

based on the concept of documents, used in document-oriented databases such as MongoDB. Best suited for data is stored in semi-structured or unstructured format.

Key-value model (KVM)

based on the concept of a key and its associated value, used in key-value stores such as Redis. Best suited for data is stored in a simple and structured format, Focus on fast and effiecient data retrieval.

Column-family model (C-FAM M)

relational model but it organizes data into columns instead of rows, Best suited data is stored in a simple and structured format, Focus fast and efficient data retrieval.

Database Management System (DBMS)

software that manages the storage retrieval, manipulation of data, Also provides interfaces to interact with the data.

Database

where the Data is actually stored.

Data Model

defines the structure and relationships of the data stored in the database, Most common data model (relational model).

Application Interface

interface that users and applications use to access and manipulate the data in the database.

Data Access Layer

layer of software that sits between the application interface and the DBMS, Main function to provide a way for the application to access the data.

Query Optimizer

responsible for determining the most efficient way to execute a query, choosing the best indexes to use, selecting the most efficient algorithms.

Backup and Recovery System

responsible for making backups of the database and for restoring the database.

Security System

responsible for controlling access to the data in the database, Ensuring the integrity and confidentiality of the data.