Young-han Kim's Practical Database - Design Part 1, Complete Mastery of Modern Data Modeling

"A query that ran perfectly during development suddenly slows down as data accumulates." At such times, the mark of a truly skilled developer is identifying the root cause based on solid evidence rather than guesswork, and optimizing a 30-second query down to 0.1 seconds. Master the core principles of database performance—from execution plans, indexes, and optimizers to joins and sorting—using millions of rows of real-world data. Elevate your skills and become a top-tier developer capable of independently analyzing and resolving slow queries in production environments.

Not only developers, but also planners and data analysts learn databases step-by-step, starting from the basics of SQL.

Learn practical core Java object-oriented concepts easily via example code.

Solve the challenges you inevitably face in real-world design—such as common codes, category hierarchies, history tracking, soft deletes, statistics, dynamic design, and JSON utilization—with 9 core patterns. This is not just simple theory; it contains practical know-how and selection criteria for various scenarios, proven across numerous projects. Now, become a true design expert who can confidently handle any requirement that comes your way.

Learn the fundamentals of SQL and databases essential for practical work. Not only developers, but also planners and data analysts can learn SQL in depth.

This is a Java course for those who are new to programming. You can easily learn Java by following along with the code.

You can understand all the web technologies required for web application development from the basics and complete your learning. In MVC Part 2, you can learn all the practical application techniques needed for real-world web development, building upon the core principles and structures from MVC Part 1.

Learn Java generics and collection frameworks in depth with a focus on practical applications. Also learn the basics of data structures.

Learn the core HTTP features essential for practical use and how to design proper HTTP APIs.

Spring beginners can grasp core principles and solidify basics via examples.

Beginners to Spring can quickly learn the entire Spring web application development process by creating examples.

This book provides an in-depth study of various intermediate-level Java features necessary for practical work, using example code.

This course will cover everything you need to know about Spring Boot for practical use.

For those who are new to JPA or who use JPA in practice but lack basic theory, By learning the basic theory of JPA solidly, even beginners can confidently use JPA in practice.

You can understand and master all the web technologies required to develop web applications from the basics. You can understand the core principles and structure of Spring MVC and grow into a more in-depth backend developer.

You will learn the core principles and advanced technologies of Spring in depth and be able to use Spring confidently.

This course provides an in-depth study of multithreading and concurrency, from basic principles to practical applications.

Learn the essential modern Java technologies of Lambda, Stream, and functional programming with Java, from the basics to the practical level, in depth.

With a practical example, we will design and develop a web application using Spring Boot and JPA. Through this process, you will understand how to use Spring Boot and JPA in practice.

Learn I/O, networking, reflection, and annotations in depth, from the basics to the practical level. Build a web application server (WAS) directly in Java.

Solve the challenges you inevitably face in real-world design—such as common codes, category hierarchies, history tracking, soft deletes, statistics, dynamic design, and JSON utilization—with 9 core patterns. This is not just simple theory; it contains practical know-how and selection criteria for various scenarios, proven across numerous projects. Now, become a true design expert who can confidently handle any requirement that comes your way.

Learn the fundamentals of SQL and databases essential for practical work. Not only developers, but also planners and data analysts can learn SQL in depth.

SQL data analysis! We will teach you how to solve practical problems that are applicable in the field, quickly and easily!

A must-have subject for aspiring developers and those looking to get a job in big data!!

I have summarized the essential SQL SELECT statements and basic usage of Google Sheets that I learned while working as an analyst at a service company.

In this lecture, we aim to create a Web Scraping API server using the Naver Shopping site. We will show you how to configure a managed API server by connecting MySQL and configuring a 3-tier architecture!!

This course goes beyond simple CRUD-level database usage to help you acquire PostgreSQL skills necessary for the AI era from a practical perspective. Based on AI development experience in Silicon Valley, you will learn step-by-step how to design and utilize JSON, indexes, transactions, and even pgvector in real-world services, while mastering methods to solve complex data structures and performance issues.

This lecture comprehensively organizes the content that would be good for those who want to get a job as a new Spring Java backend developer, especially those who are about to have an interview.

This is a content about backend development using two databases, MySQL and Mongo, for job seekers preparing for backend employment.

By implementing a first-come, first-served coupon system, you will solve core real-world backend challenges such as concurrency issues, data integrity, and peak traffic handling. You will discover problems by writing code yourself and gain hands-on experience with essential industry skills like synchronous/asynchronous processing and queue management. This is a project-based course designed for junior developers and job seekers to build practical experience.

SQLD Yellow Book 176 Problem-Solving Course for those who studied but can't solve problems. After completion, you'll go beyond passing to become an expert. SQLD All-in-One Pass!

By implementing various practical data analysis cases using SQL, you can simultaneously improve your data analysis and SQL utilization skills.

This is a full-stack restaurant map tutorial that allows you to learn everything from front-end, back-end, Kakao Map API usage, and deployment all at once while creating a restaurant map of your favorite YouTuber.

SQLD, where should I start? For those of you feeling completely overwhelmed, this is the lecture for you. You will meet a transformed version of yourself after completing the course. SQLD All-in-One Pass!

This course proceeds in stages where you learn and apply necessary knowledge while building infrastructure, similar to real-world practice.

Learn common components of global-scale services through popular papers, books, and articles.

Just listen. The lecturing skill, captivating power, and lecture quality are different.

This is a special lecture that can lay the theoretical foundation to simultaneously prepare for the Microsoft AZ-900 certification, and as the latest content reflecting the scope of questions as of May 2025, by providing content related to core data concepts, Azure's relational data, Azure's non-relational data, and Azure's analytical workloads in a form combining theory and practice, it can be utilized as a meaningful educational opportunity to not only obtain the certification but also take the first step towards becoming a data professional.

How does the architecture change when an LLM is integrated into an existing backend? This is an introductory system design course that goes beyond simple LLM API calls to help you understand core AI service components such as Model Routers, LLM Gateways, and Vector DBs, and step-by-step design an operational AI service architecture including RAG and AI Agents. It is designed to help those who want to create their own LLM-based AI services quickly master the design workflow.

A guide to the exam for nationally recognized SQL qualifications! Establish a comprehensive knowledge system related to SQL.