Hung Hoang

A declarative approach is a way that focuses on writing code that specifies what the application should do, rather than detailing how it should be done. For example, with the async pipe in Angular, we don’t need to write code to manually subscribe to an Observable, handle its data, and update the view. Instead, we simply specify in the template that we want the data from the Observable using the async pipe. Angular handles all the underlying processes to retrieve and display the data It's often used in reactive programming with RxJS and Angular's built-in features, such as the async pipe. export class ProductComponent { product$ = this.productService.getProduct(); constructor(private productService: ProductService) {} } The product observable will hold the product data and the async pipe in the template will automatically subscribe and unsubscribe observable <div *ngIf="product$ | async as product"> <h1>{{ product.name }}</h1> <p>{{...

Deferred Execution means that queries are not executed immediately at the time it's being created. The benefit of this is to improve performance by avoiding unnecessary executions. It also allows the query to be extendable when needed such as sorting, filtering. In the example below, the queries to retrieve courses are not being executed yet var context = new DbContext(); var courses = context.Courses      .Where(c => c.Level == 1)      .OrderBy(c => c.Name); The query is only executed when one of the following scenarios occurs: Iterating over query variable Calling ToList, ToArray, ToDictionary Calling First, Last, Single, Count, Max, Min, Average For example when we loop through the course or turn the result to a list: foreach ( var c in courses) Console.WriteLine(c.Name); OR context.Courses      .Where(c => c.Level == 1)      .OrderBy(c => c.Name).ToList();

For a successful IT project there are several key criteria, which are fundamental constraints serving as the project’s backbone. It’s important to recognize and prevent factors that contribute to ‘scope creep', a common pitfall in project management. Additionally, taking into account vital elements beyond the traditional triple constraints that are crucial for the success of the project. What is The Triple Constraint? The Triple Constraint is the Project Management Triangle ( Iron Triangle ), a model of the constraints inherent in managing a project and consists of three primary elements: Cost, Scope, and Time Cost:  The project budget Scope: The tasks required to fulfill the project’s goals Time: The schedule for the project to reach  The purpose of the Triple Constraint is to provide a framework for project managers to make informed decisions throughout the project lifecycle. It guides project planning by helping project managers establish realistic goals and objectives. I...

What is database performance? There are two main aspects of database performance: response time and throughput . Response time is the total time it takes to process a single query and returns result to the user. It's critical metrics because it directly impacts the user's experience, especially in applications where fast access to data is essential. The response time includes CPU time (complex queries will require more computational power and increase processing time), disk access, lock waits in multiple-user environment (more about database transaction ), network traffic. Throughput refers to how many translations the system can handle per second (TPS). A transaction could include different activities to retrieve and manipulate data. A single command like SELECT, INSERT, UPDATE, DELETE or a series of commands could be used to trigger these activities. If you’re running an e-commerce site, a single transaction might include checking the inventory, confirming the payment, and...

 1. What is database translation Database transactions are activities transferring, changing data from one consistent state to another consistent state for example in everyday life we make different kind of business transactions from buying products, changing or cancelling orders, buying tickets, etc. And all these activities involve the movement/transaction of data in the database. For example, consider a simple transaction of moving an amount of 5000 from one bank account to another. This transaction includes several steps: decrease the account balance by 5000, and then increase the other account balance by 50003. Each of these steps is a part of the transaction, and if any step fails, the entire transaction fails 2. Why it is crucial in reliable software systems? When it comes to business, whether it is personal or financial data, it is crucial to ensure the reliability and stability of data management. In our daily lives, we may frequently encounter errors related to database t...

What is Database Normalization? Database normalization is an approach to evaluate database structure and minimize data redundancy based on candidate keys and functional dependencies. Candidate keys are unique identifiers that have all the necessary conditions to become a primary key. Functional dependencies refer to the relationship between attributes, where one attribute uniquely determines another. Simply put normalization is a process of eliminating attributes which is not identified by candidate keys . For example, consider a studentnumber  that can uniquely identify a surname and firstname . In this case, the student number acts as a determinant , which determines the surname or firstname. Student ( studentnumber , surname, firstname) The goal of normalization is to group attributes with a close logical relationship into the same table, so that it ensure there is no data redundancy. Benefits: Efficiently retrieve data: Well-structured data allows for faster and more accurat...