================
What is Cache 
=================

=> Every application will contain two types of tables

        1) Transactional tables

        2) Non-Transactional tables

=> If our application is performing DML operations on the table then those tables are called as Tx tables.

        Ex: products_tbl, orders_tbl, users_tbl ....        


=> If our application is performing only DQL (Select) operations on the table then those tables are called as Non-Tx tables. These are also called as static tables.

        Ex: country_tbl, states_tbl ....


=> It is not recommended to read static data from DB table everytime. Because DB call is costly operation which will reduce performance of the application. 

    (driver loading + connection + query execution + data process + conn close)

Usecase : Read countries from db table and display in application registration page as drop down options.

Note: To improve performance of the application we need to maintain cache. 

==============
Redis Server
===============

=> Redis means Remote Dictionary Server.

=> It is an open source in-memory data store.

=> It is used as database, cache, message broker...

=> The main purpose of REDIS Cache is used to improve performance of our application by simplifying read and write operations.

=> Redis is known for its speed, flexibility, and ease of use.

=> It is one stop solution when we want to perform quick read and write operations.



===============
RDBMS Vs Redis
===============

=> We will use RDBMS for below scenarios

1) Structured data
2) Tables, Rows and Columns
3) Complex Queries
4) Joins
5) Relationships are very imp

=> We will use Redis for below scenarios

1) Fast Read & Write Operations
2) Key-Value format
3) Relationships are not important
4) Transactions are not important
5) Performance is important


===================
Redis Server Setup
===================

=> Setup Redis DB Using Redis cloud

    Login URL : https://cloud.redis.io/#/login

    Note: Sign in with google


=> After login, create database with 30 MB (free of cost)    

    Redis Endpoint URL : redis-16905.c81.us-east-1-2.ec2.redns.redis-cloud.com:16905

    username: default

    password: Q4v9GqpC54RBMZIRMmRBM4DQI57GcL8Y

Note: Our Redis Server is ready in cloud, now we can develop SpringBoot application to connect with Redis Server.    

===================================
Spring Boot with Redis Integration
===================================

@@ Spring Boot + Redis DB Git Repo :: https://github.com/ashokitschool/SpringBoot_Redis_Cloud_DB_App.git

## Step-1 : Create springboot app with below dependencies

        a) web-starter
        b) starter-data-redis
        c) jedis
        d) devtools

<dependency>
    <groupId>redis.clients</groupId>
    <artifactId>jedis</artifactId>
</dependency>           

## Step-2 :: Configure redis db server details in application.properties file           

spring.data.redis.url=redis-16905.c81.us-east-1-2.ec2.redns.redis-cloud.com
spring.data.redis.port=16905
spring.data.redis.username=default
spring.data.redis.password=Q4v9GqpC54RBMZIRMmRBM4DQI57GcL8Y


## Step-3 :: Create RedisConfig class to establish connect with Redis Server

## Step-4 :: Create Entity to represent data (@RedisHash)

## Step-5 :: Create Repository to perform CRUD operations

## Step-6 :: Create REST Controller with HTTP methods

## Step-7 :: Test the application from postman.