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[CS Technical Interview 4] Database that gets you talking

A course that helps you understand core database concepts and trains you to explain them verbally in interviews.

(5.0) 20 reviews

441 learners

Level Beginner

Course period Unlimited

SQL
SQL
DBMS/RDBMS
DBMS/RDBMS
Tech Interview
Tech Interview
SQL
SQL
DBMS/RDBMS
DBMS/RDBMS
Tech Interview
Tech Interview

Reviews from Early Learners

5.0

5.0

KJH

100% enrolled

You did a great job highlighting the key points within the short lecture time, which was very helpful. I really like how you always summarize everything once more at the end. Thank you.

5.0

든든한꼬마

100% enrolled

I knew how important databases are for developers, but I always found it boring whenever I studied the theory in this field. Yongjun's lecture explained the core database theory concisely and clearly, allowing me to learn with interest. The explanations through real-world examples were a great help in understanding the theory intuitively! I'm also taking the SQLD exam soon, and I think this will be very helpful for exam preparation as well. Thank you for the great lecture.

5.0

인섭

83% enrolled

It was great that you covered not only simple SQL syntax but also transactions and permissions. Especially when talking about databases, you can't leave out indexes, and it was a substantial lecture since it included discussions about indexes as well.

What you will gain after the course

  • Understanding Core Database Concepts

  • The ability to explain verbally in technical interviews

  • Practical Workbook PDF for Preparing for Follow-up Questions

Have you ever had an experience like this in an interview?

1. When answering with confused concepts

❓Interviewer What are the characteristics of object-oriented programming?
💬 Candidate It's the SOLID principles. First, S is...(omitted)...

This is a situation where the characteristics of object-oriented programming (abstraction, encapsulation, inheritance, polymorphism) and
the object-oriented design principles (SOLID) have been confused.
This can give the impression that the framework of basic concepts has not been established.

2. Knowing only the 'What' but failing to explain the 'How' or 'Why'

❓Interviewer: What are the characteristics of TCP?
💬 Candidate: It is a protocol that guarantees reliability.
❓ Interviewer: What are the mechanisms that guarantee reliability?
💬 Candidate: Uh... well... it's like... making sure it's transmitted safely... sort of...

This is a state where you only know the superficial definition and are not prepared to explain the principles.
If the 3-way handshake, sequence numbers, ACK, retransmission, flow control, and congestion control
are not connected as a single flow, you will inevitably get stuck on follow-up questions.

3. When you get tongue-tied on basic questions

❓Interviewer: What is HTTP?
💬 Candidate: Uh… it's for… sending and receiving data on the web…?

It is a very familiar concept, but when you actually try to explain it in a single sentence, the words don't come out.
This is not a lack of knowledge, but a lack of experience in organizing and speaking it out.


Knowing it is not enough. It only becomes a true skill when you can explain it in words.

🔥 So, this is how it's structured.

✦ Next-level, premium content for interview preparation

1⃣ CS Notes Organized Specifically for Interview Preparation

  • Concepts and principles that must be checked before an interview are gathered together and provided as lecture materials.

  • While building a solid foundation, it is structured so that you can keep coming back to it right until the moment of your interview.

  • It is not a simple summary, but includes diagrams and easy explanations so that even non-majors can fully understand it.


Example of Computer Architecture Lecture Materials

2⃣ Appendix | Interview Practice Materials Provided

  • In an interview, the ability to explain clearly is much more important than simply knowing the information.

  • However, organizing and practicing on your own is a difficult and tedious task.

  • At the end of the lecture materials, we have included "one-to-two sentence answer" training to save you the trouble of organizing it yourself.


Example of Database Lecture Appendix

3⃣ Preparing for follow-up questions Technical Interview Practical Workbook PDF providedchuẩn bị cho cả các câu hỏi phụ

  • "Will this lecture alone really be enough for speaking practice?"
    After much deliberation,

    I have created a technical interview practical workbook.

  • It is designed so that you can practice speaking just like a real interview even by yourself.

  • You can find detailed information on the structure and usage of the workbook in the workbook introduction video at the beginning of the lecture.

Operating System Workbook Example

4⃣ A CS learning app for reviewing anytime, anywhere

To ensure you don't forget the core concepts learned in the lecture,
a dedicated mobile learning app is also provided.

You can naturally review by repeatedly studying quizzes and core concepts during your commute or even during short breaks
.

💡 How to make the most of this abundant content

1⃣ Download the materials and learn the core concepts while listening to the lectures.
2⃣ Take your own notes on important parts to create your own CS interview notes.
3⃣ Save them on your phone and review them briefly whenever you have a spare moment.

If you have an interview coming up and
are short on time → Quickly sharpen your interview instincts with the Appendix [Interview Practice] in the lecture materials.
If you have enough time → Perfect your speaking practice like a real interview with the Technical Interview Practical Workbook and Mobile App.

🎯 Recommended for the following people

Non-majors, job seekers, career changers, etc., who are preparing for technical interviews and need to be able to explain CS fundamentals verbally

CS majors who need to organize their knowledge again

I've studied it before, but
I don't even know where to start organizing all that CS knowledge

Don't open those thick textbooks
ever again.
We will organize only the core essentials clearly.

Non-majors who feel overwhelmed by CS

I'm preparing for a technical interview for the
first time, so I'm overwhelmed and don't know
where to start

By following the roadmap,
you can focus on learning
only the key CS core concepts.

Job seekers looking to change careers with limited time

Forget that, I don't have much time.
I need to
quickly summarize only the CS topics that appear in interviews.

There are lecture materials and interview chapters that allow for
quick review
even on your own.

🔥 Reviews from students who experienced it first

A truly helpful lecture.
Already proven by 5,000+ students.

⭐️⭐️⭐️⭐️⭐️

1. A lecture where you can see how much the author has thought and agonized from the student's perspective (it seems the learner's flow of understanding was well-considered)
2. Understanding is easy due to the variety of visual materials and examples
3. When learning new knowledge, previously learned content is mentioned and recalled to connect the information. As the knowledge connects, a big picture is formed.
4. The depth of knowledge is not shallow. I'm taking the Operating Systems course right after Computer Architecture, and the synergy is great.
5. It perfectly scratches the itch of wondering "why" & "why we use it."
ps. I'm sorry to the author, but.. it's a lecture I want to keep all to myself.

- 'Operating Systems' Course Review

⭐️⭐️⭐️⭐️⭐️

Even with a short lecture time, it's great how the important parts are explained clearly. Since it's mostly theory-based, I didn't expect SQL queries to be covered, but I really liked how the basic syntax and query writing were taught with step-by-step examples. After that, the sections on joins, normalization, transactions, indexes, data optimization, and security were excellent. Although I haven't taken other paid courses yet, the last lecture appendix titled "Interview Practice" provided actual questions and answers, making it great for self-study and practice. The lecture time isn't too long if you stay focused, so I think I'll watch it a few more times. Thank you.

-'Database' Course Review

⭐️⭐️⭐️⭐️⭐️

The core content was explained so clearly and with such a logical flow that it helped me quickly organize my understanding of data structures. Thank you for the great lecture.

-'Data Structures' Course Review

⭐️⭐️⭐️⭐️⭐️

Wow... this is seriously so good...;;;; I need to save up and buy the whole roadmap.. I'm curious if you have any plans to teach Spring as well.. I'll buy it immediately..

- Review for 'Java and Object-Orientation'

⭐️⭐️⭐️⭐️⭐️

This is a lecture where you can set aside a day to organize the key concepts of JavaScript all at once! It's great for a quick reminder before an interview👍



-'JavaScript' Course Review

⭐️⭐️⭐️⭐️⭐️

As a non-CS major, I was worried about how to study CS knowledge, especially computer architecture and operating systems, but the content was a manageable amount so I could learn without feeling overwhelmed, and it was great because it felt like getting private tutoring from an expert. I'm planning to take the operating systems lecture as well, and I'm looking forward to it. Thank you!

-'Computer Architecture' Course Review

🖐 Hello! Let me introduce myself! 🙇

As a non-major, I initially focused solely on algorithms and coding tests while preparing for my first job as a developer.
I gained a fair amount of confidence and passed most coding tests, but I repeatedly failed at the next hurdle: the technical interview. What was the problem? It was the lack of CS (Computer Science) knowledge.

I understand the thirst for fundamental skills (CS knowledge, programming languages, etc.) better than anyone. I built up my own know-how by digging through countless materials on my own, and eventually, after graduating from Seoul National University, I am working as a 🧑🏻‍💻 Kakao Developer.

Since I was young, I have been more confident than anyone else in combining and restructuring various materials to create my own 'consolidated notes.' This lecture is the secret notebook that contains all that know-how and passion.

🚀 The fourth subject of the CS Series for Fluent Speaking is Database.

  • Do you have trouble remembering transaction isolation levels and the specific problems solved at each stage?

  • Have you been glossing over sharding as vertical partitioning and partitioning as horizontal partitioning?

  • Or do you know that indexes are good for performance, but find their complex structure and operating principles still confusing?

📖 A curriculum packed with only the essentials gói gọn những nội dung cốt lõi

This is the table of contents and key keywords you will learn in this lecture.

If there are any unfamiliar keywords, take this opportunity to master them once and for all.

  1. Database Overview

    • Database characteristics, RDBMS, database modeling

  2. Handling SQL

    • SQL Basics CRUD, Aggregate Functions, Subqueries, SQL Joins, Paging, NoSQL

  3. Normalization

    • Anomalies, various normalization stages (1NF~3NF)

  4. Transaction

    • ACID, transaction states, transaction recovery, transaction isolation levels (Level 1 to Level 4)

  5. Index and Data Optimization

    • Index types and data structures (B-Tree, B+Tree), composite indexes, sharding, and partitioning

  6. Database Security

    • User privilege management, SQL injection defense

  7. [Appendix] Interview Practice

    • Review key concepts once more in a Q&A format

✏ Here is what we will cover

1⃣Database Fundamentals Summary for Both Practical Work and Interviews

  • Organize core concepts such as SQL, normalization, transactions, index, sharding, and security into a logical flow.

  • Designed with a focus on the conceptual context (why this feature was created)

강의 상세 목차

Detailed Course Curriculum

2⃣ 'Knowing 'Why' You Use It: Learning Core SQL Syntax and Principles

  • Beyond simply listing SQL syntax, you will learn the significance of core SQL grammar, such as why we use JOIN and in what situations GROUP BY is necessary..

  • You will gain a clear understanding of the context in which SQL syntax is frequently used in practice, ranging from basic SELECT, INSERT, UPDATE, and DELETE to complex JOIN, subqueries, and paging queries.

Inner Join 과정

Inner Join Process

SQL 기본 문법 예시

Examples of basic SQL syntax

SQL 고급 문법 예시

Examples of Advanced SQL Syntax

3⃣Easy explanations of confusing DB concepts (transactions, normalization, indexes, etc.) using diagram-centered visuals

  • We will clearly understand the characteristics of each isolation level, the stages of normalization (1st, 2nd, 3rd normalization), and anomalies that many beginners struggle with, as well as the complex data structures (B+Tree) and operating principles of indexes, through intuitive diagrams and visual aids instead of complex text.

  • We help you understand and remember each concept for a long time by allowing you to grasp at a glance through illustrations why they are necessary, what problems they solve, and how they impact actual performance.

인덱스의 B+tree 자료구조

B+tree data structure of an index

이상 현상 예시

Examples of anomalies

트랜잭션 격리 수준 예시

Examples of transaction isolation levels

👀 Course Preview

If the video is frozen, please refresh the page :)

Explanation of the DB modeling process

Explanation of Transaction Isolation Levels 1 to 4

말이트이는 CS 시리즈

Things to note before taking the course

  • Format of provided learning materials: PDF

Recommended for
these people

Who is this course right for?

  • A non-major who feels overwhelmed because it's their first time studying CS

  • Computer science students who need to organize CS concepts before a technical interview

  • Job seekers preparing for a career change who are short on time ahead of a technical interview

Hello
This is yiyj10305235

Inflearn Verified

Career Verified

5,710

Learners

235

Reviews

32

Answers

4.9

Rating

7

Courses

Education and Experience

  • Graduate of Seoul National University

  • Current Kakao Server Developer

    Course Introduction I am creating the "Fluent CS" series to help you articulate CS concepts during interviews. Course Philosophy Having started development as a non-computer science major, I understand the importance of CS...

Course Introduction I am creating the "CS for Speaking" series to help you articulate CS concepts during interviews. Course Philosophy Having started development as a non-computer science major, I...

Course Introduction

I am creating the
CS Speaking series to help you articulate CS concepts during interviews.

Teaching Philosophy

I started my development career as a non-CS major and went through a lot of trial and error while personally organizing everything from CS fundamentals to technical interviews. Based on the learning methods and conceptual organization know-how accumulated through that process, I create content that makes core concepts encountered in practice and interviews easy to understand through illustrations.
"I am creating the lectures that I needed back then."

Blog yiyj1030.tistory.com → Running a tech blog that simplifies CS, algorithms, and practical concepts. Contact yiyj1030@gmail.com

Blog

  • yiyj1030.tistory.com
    → Running a tech blog that simplifies and organizes CS, algorithms, and practical concepts

Contact

yiyj1030@gmail.com

More

Curriculum

All

32 lectures ∙ (3hr 19min)

Course Materials:

Lecture resources
Published: 
Last updated: 

Reviews

All

20 reviews

5.0

20 reviews

  • yji09030350님의 프로필 이미지
    yji09030350

    Reviews 91

    ∙

    Average Rating 4.5

    5

    62% enrolled

    It is a great help in understanding DB.

    • myhwc님의 프로필 이미지
      myhwc

      Reviews 3

      ∙

      Average Rating 5.0

      5

      83% enrolled

      It was great that you covered not only simple SQL syntax but also transactions and permissions. Especially when talking about databases, you can't leave out indexes, and it was a substantial lecture since it included discussions about indexes as well.

      • yiyj10305235
        Instructor

        Thank you for the course review. I hope this lecture isn't the end and that we can continue the learning journey together. I look forward to seeing you again in the next series :)

    • junkim46857399님의 프로필 이미지
      junkim46857399

      Reviews 5

      ∙

      Average Rating 5.0

      5

      100% enrolled

      You did a great job highlighting the key points within the short lecture time, which was very helpful. I really like how you always summarize everything once more at the end. Thank you.

      • yiyj10305235
        Instructor

        Thank you for the course review. I hope this lecture isn't the end and that we can continue the learning journey together. I look forward to seeing you again in the next series :)

    • koelkorea7927님의 프로필 이미지
      koelkorea7927

      Reviews 21

      ∙

      Average Rating 5.0

      5

      42% enrolled

      Since databases are used by everyone in the field, it's not easy for non-majors to try to find, study, and organize the basics, and many lectures are burdensomely expensive... This course solves all those dilemmas while remaining affordable. I especially want to recommend this to anyone curious about DB basics because it selects the core theoretical fundamentals rather than just practical work and organizes them like a set of notes.

      • leeseongmin님의 프로필 이미지
        leeseongmin

        Reviews 4

        ∙

        Average Rating 5.0

        5

        31% enrolled

        I like it

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        Practical preparation for coding tests and interviews, directly taught by interviewers from Naver, Kakao, Line, Coupang, and Baemin.Course Thumbnail

        Practical preparation for coding tests and interviews, directly taught by interviewers from Naver, Kakao, Line, Coupang, and Baemin.

        Hong

        This course was created to solve a common problem many people face while preparing for developer jobs: "I studied CS and data structures, but I get tongue-tied during interviews." While conducting actual interviews at companies like Naver, Kakao, and Toss, I noticed that most candidates have memorized concepts but cannot explain why those concepts are necessary or how they are applied in real-world situations. Rather than simple rote memorization, this course teaches you how to understand the interviewer's intent and provide more persuasive answers to the same questions. Whether it's the OSI 7 layers, data structures, or coding tests, we focus on why you need to know them, when they are used, and how to speak about them to receive a positive evaluation in an interview. This course is for those who want to become developers who can explain what they understand in their own words, rather than just giving the same answers as everyone else.

        Beginner

        Beginner

        JavaScript, Interview, Tech Interview

        Practical preparation for coding tests and interviews, directly taught by interviewers from Naver, Kakao, Line, Coupang, and Baemin.Course Thumbnail

        Practical preparation for coding tests and interviews, directly taught by interviewers from Naver, Kakao, Line, Coupang, and Baemin.

        Hong

        A Silicon Valley AI Developer's PostgreSQL for Handling 200+ Billion RecordsCourse Thumbnail

        A Silicon Valley AI Developer's PostgreSQL for Handling 200+ Billion Records

        Hong

        This course goes beyond basic CRUD-level database operations, equipping you with practical PostgreSQL skills essential for the AI era from a real-world perspective. Drawing on AI development experience in Silicon Valley, you will learn step-by-step how to design and leverage JSON, indexing, transactions, and pgvector in actual production services, and master the techniques to resolve complex data structure and performance issues.

        Beginner

        Beginner

        MySQL, PostgreSQL, Oracle

        A Silicon Valley AI Developer's PostgreSQL for Handling 200+ Billion RecordsCourse Thumbnail

        A Silicon Valley AI Developer's PostgreSQL for Handling 200+ Billion Records

        Hong

        For those who haven't even started with SQL, come hereCourse Thumbnail

        For those who haven't even started with SQL, come here

        coddatg

        Technology should also start with interest. I have prepared a story about a person who analyzes MBTI of his coworkers. I hope that those who have been daunted by SQL will start studying it with enjoyment.

        Beginner

        Beginner

        SQL, bigquery

        For those who haven't even started with SQL, come hereCourse Thumbnail

        For those who haven't even started with SQL, come here

        coddatg

        [MMORPG Game Development Series with C# and Unity] Part 5: DatabaseCourse Thumbnail

        [MMORPG Game Development Series with C# and Unity] Part 5: Database

        Rookiss

        This is a course for learning MS-SQL through baseball and corporate databases.

        Basic

        Basic

        SQL, DBMS/RDBMS

        [MMORPG Game Development Series with C# and Unity] Part 5: DatabaseCourse Thumbnail

        [MMORPG Game Development Series with C# and Unity] Part 5: Database

        Rookiss

        Large-Scale Systems Design Part 1Course Thumbnail

        Large-Scale Systems Design Part 1

        Jayce

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

        Basic

        Basic

        software-design, DBMS/RDBMS

        Large-Scale Systems Design Part 1Course Thumbnail

        Large-Scale Systems Design Part 1

        Jayce