1. Introduction This document summarizes knowledge and experience on database query optimization, focusing on using EXPLAIN, EXPLAIN ANALYZE, table access methods, and index optimization. It's suitable for developers and DBAs who want a deep understanding of how databases execute queries and techniques to improve performance. 2.1 Execution Plan with EXPLAIN The execution plan reveals how … Continue reading How PostgreSQL Executes Your Queries: EXPLAIN, ANALYZE, and Index Strategies →

I. Diagram II. Detailed Steps 1. Setup the SQS dead-letter queues Step 1: Create the SQS queue with the name ap-demo-main. Step 2: Create the second SQS queue with the name ap-demo-main-DLQ. Step 3: Back to the queue ap-demo-main, go to the Dead-letter queue, then select the Edit button. Step 4: On the new screen, … Continue reading Using SQS dead-letter queues to replay messages →

For the detailed of lambda function, please visit the link: https://docs.aws.amazon.com/lambda/latest/dg/welcome.html Step 1: Install the .NET CLI Templates for AWS Please use the following command below to install: dotnet new -i Amazon.Lambda.Templates Step 2: Install The AWS .NET Mock Lambda Test Tool Please visit the page below for more information: https://github.com/aws/aws-lambda-dotnet/blob/master/Tools/LambdaTestTool/README.md Step 3: Create the … Continue reading Create and deploy the first simple lambda via the MS Visual Studio. →

I. IntroductionThis guide will walk you through setting up the essential tools and environment for working with AWS. From creating a free-tier AWS account to configuring the AWS CLI and installing development toolkits, each step is designed to get you up and running quickly. Whether you're using Visual Studio, VS Code, or JetBrains Rider, this … Continue reading Setup AWS tool on your local machine. →

I. Introduction Elasticsearch and Kibana are powerful tools often used together to monitor, read, and analyze system logs. They provide a robust solution for logging and monitoring, especially in environments with large amounts of data. II. How do you set up Kibana and Elasticsearch on the local machine? Step 1: Please visit these links below … Continue reading How do you set up Kibana and Elastic search on the local machine to read the log files? →

I. The Scenario That SemaphoreSlim Can Help You Solve Below is a clear explanation that would help you understand the situation where you should use SemaphoreSlim (reference [1]). In the kindergarten around the corner they use a SemaphoreSlim to control how many kids can play in the PE room. They painted on the floor, outside … Continue reading Understanding and Using SemaphoreSlim in C# →

I. Why do we need the method chaining mechanism First of all, please see some examples in real-world applications which are using the method chaining mechanism. // Example 1: var result = Employees.Where(a => e.Name == "Tim Nguyen") .OrderBy(a => e.PhoneNumber == 0123456789) .ToList(); // Example 2: // The code below is to declare the … Continue reading Getting started with method chaining in C# →

I. Overview To know what Codespaces is, you can check the official introduction here:👉 https://github.com/features/codespaces II. Actions Step 1 From the main page, navigate and select the Codespaces menu to access your codespaces. Step 2 In the new window, select the button New codespace. Step 3 Hit the button Create codespace with the following configurations: … Continue reading Getting started with GitHub codespaces →

Below is a mapping between program elements in C# and their corresponding UML diagram elements, along with the meaning of each. UML Elements Table Program elementDiagram elementMeaningClassType and parameters specified when important; access indicated by + (public), - (private), # (protected).InterfaceName starts with I. Also used for abstract classes.NoteAny descriptive text.PackageGrouping of classes and interfaces.InheritanceB … Continue reading UML Short Description →

Hi!,First of all, I would like to say the content above is an essential thing for each developer who wants to improve their code quality.I do not own the content above, I just bring it from the Lars Kappert's GitHub.Please see the References section for the reference to GitHub and the owner's websites. Programming Principles … Continue reading Programming Principles →