Data Nexus

 Sure! Let's start by creating a sample table and then go through ORDER BY , GROUP BY , HAVING , and WHERE clauses in detail with 10 examples . Step 1: Create a Sample Table We will create an employees table to work with. CREATE TABLE employees ( id INT PRIMARY KEY, name VARCHAR(50), department VARCHAR(50), salary INT, experience INT ); Step 2: Insert Sample Data INSERT INTO employees (id, name, department, salary, experience) VALUES (1, 'Alice', 'HR', 60000, 5), (2, 'Bob', 'IT', 75000, 3), (3, 'Charlie', 'IT', 65000, 7), (4, 'David', 'Finance', 50000, 2), (5, 'Eve', 'Finance', 70000, 6), (6, 'Frank', 'IT', 80000, 8), (7, 'Grace', 'HR', 45000, 4), (8, 'Hank', 'IT', 90000, 9), (9, 'Ivy', 'Finance', 60000, 3), (10, 'Jack', 'HR', 55000, 6); Step 3: Understanding Clauses 1. WHERE Clause Filters...

  Deploying a Personal Website on AWS EC2 with Apache Introduction Hosting a personal website on AWS EC2 using Apache is a great way to showcase your portfolio, resume, or blog. This guide walks you through setting up an Ubuntu EC2 instance, installing Apache, deploying a static website, and customizing your content. Step 1: Launch an EC2 Instance Sign in to AWS Console and navigate to the EC2 Dashboard . Click "Launch Instance" and configure: AMI: Ubuntu (Latest LTS) Instance Type: t2.micro (Free Tier eligible) Security Group: Allow SSH (22), HTTP (80), and HTTPS (443) Key Pair: Download the .pem file for SSH access. Launch the instance and note the Public IP/DNS . Step 2: Connect to EC2 via SSH Use the command below to access your instance: ssh -i "your-key.pem" ubuntu@your-public-ip Replace your-key.pem with your key file and your-public-ip with the EC2 instance's public IP. Step 3: Install Apache Web Server Update packages an...

  AWS SQS and SNS: A Complete Guide to Messaging Services Introduction AWS provides two powerful messaging services, Simple Queue Service (SQS) and Simple Notification Service (SNS) , for building scalable, decoupled, and event-driven applications. While SQS is a fully managed queuing service that enables asynchronous communication, SNS is a pub/sub messaging service for sending notifications and alerts. AWS SQS (Simple Queue Service) What is AWS SQS? AWS SQS is a message queuing service that allows components of a distributed application to communicate asynchronously. It ensures reliable message delivery between services, even if they are running at different speeds. Key Features of AWS SQS Fully Managed : AWS handles scaling and availability. Decoupling : Separates application components for better scalability. FIFO & Standard Queues : Ensures message ordering when needed. At-least-once Delivery : Guarantees message delivery. Dead-letter Queues (DLQ) : Stores f...

  AWS SQS and SNS: A Complete Guide to Messaging Services Introduction AWS provides two powerful messaging services, Simple Queue Service (SQS) and Simple Notification Service (SNS) , for building scalable, decoupled, and event-driven applications. While SQS is a fully managed queuing service that enables asynchronous communication, SNS is a pub/sub messaging service for sending notifications and alerts. AWS SQS (Simple Queue Service) What is AWS SQS? AWS SQS is a message queuing service that allows components of a distributed application to communicate asynchronously. It ensures reliable message delivery between services, even if they are running at different speeds. Key Features of AWS SQS Fully Managed : AWS handles scaling and availability. Decoupling : Separates application components for better scalability. FIFO & Standard Queues : Ensures message ordering when needed. At-least-once Delivery : Guarantees message delivery. Dead-letter Queues (DLQ) : Stores f...

  AWS EMR (Elastic MapReduce): A Comprehensive Guide Introduction AWS EMR (Elastic MapReduce) is a cloud-based big data processing service that simplifies running large-scale distributed data processing jobs using open-source frameworks like Apache Spark, Hadoop, Hive, and Presto. It is designed to handle petabyte-scale data efficiently with cost-effective and auto-scalable clusters. Key Features of AWS EMR Scalability : Automatically scales clusters based on workload. Cost-Effective : Uses EC2 Spot Instances to reduce costs. Integration : Supports S3, DynamoDB, Redshift, and more. Managed Service : AWS handles cluster provisioning and management. Security : Integrated with IAM roles, encryption, and VPC. Flexibility : Supports multiple frameworks like Spark, Hadoop, Hive, Presto. AWS EMR Architecture AWS EMR follows a master-worker architecture: Master Node : Manages cluster, schedules jobs, and monitors tasks. Core Nodes : Executes tasks and stores data on HDFS. ...

  AWS EC2: A Beginner's Guide to Creating and Connecting an Instance What is AWS EC2? Amazon Elastic Compute Cloud (EC2) is a web service that provides secure, resizable compute capacity in the cloud. It allows users to run virtual servers (instances) on demand, eliminating the need for on-premise hardware. Features of AWS EC2: Scalability : Scale instances up or down based on demand. Security : Integrated with AWS Identity and Access Management (IAM) and Security Groups. Cost-effective : Pay-as-you-go pricing model. Multiple instance types : Optimized for various workloads (general-purpose, compute-optimized, memory-optimized, etc.). Elastic IPs : Static IPs that can be remapped to different instances. Auto Scaling : Automatically adjust capacity to maintain steady performance. How to Create an EC2 Instance in AWS Follow these steps to set up an EC2 instance: Step 1: Log in to AWS Console Go to AWS Console . Sign in using your credentials. Navigate to the EC2 Das...