
Spring Core Principles - Basic Edition
yh
$68.20
Basic / Spring, oop
5.0
(4,887)
Spring beginners can grasp core principles and solidify basics via examples.
Basic
Spring, oop
"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.
1,194 learners are taking this course
Level Intermediate
Course period Unlimited
The ability to read an execution plan and independently diagnose the cause of a slow query.
The ability to independently design indexes tailored to specific situations.
Real-World Experience in Optimizing Queries by 10x to 100x Across Millions of Data Records
Understanding Database Internals Beyond Indexes
Kim Young-han's Practical Database
3 million members, 5 million products
The service is growing day by day, but
what if the speed keeps getting slower and slower?!
Amidst the massive volume of data, the queries that have become bottlenecks...
How can we solve this?
If you've hit a fundamental limit in database performance
An accurate diagnosis and tuning strategy is
required.
That's why we've prepared
The final stage of database learning is
ultimately performance.
Once you learn to write queries, everyone eventually hits the same wall.
'I know I wrote it right, so why is it so slow?'
This is exactly why performance optimization is the final topic in the database roadmap.
Once you see with your own eyes how queries are actually executed and why indexes are so fast,
only then can you truly say you properly handle databases.
With a solid guide tailored to real-world practice, we'll help you complete the final step of your database journey.
By taking this course,
I created an index, but why does the optimizer ignore it?
Even when the index is hit perfectly, why is it still slow?
EXPLAIN results, where should I start reading?
Can a single join order really turn 0.01 seconds into 22 seconds?
Why does it suddenly slow down just by adding an ORDER BY?
As you page further along, why does it get increasingly slower?
POINT 1
Discover the true cause of slow queries and resolve them by applying the right principles.
STEP 01
Understand how queries are executed internally within the database, and accurately diagnose the root causes of performance bottlenecks using EXPLAIN and EXPLAIN ANALYZE.
STEP 02
Understand why indexes are fast by examining the B+Tree structure, and identify why they might still be slow even when used, enabling you to design composite and covering indexes.
STEP 03
Learn how to resolve performance issues across different query types, from retrieval and search to joins, sorting, paging, and grouping.
POINT 2
Imagine you've just joined a rapidly growing e-commerce company.
This course is designed to help you develop practical skills by working together to solve various performance issues you'll encounter in the field,
honing your real-world expertise.
4 Hands-On Tuning Exercises to Solve Problems Directly Using the Principles You've Learned
Tuning 01 · Execution Plan
🛒 Admin Order Inquiry
Quickly retrieve only the necessary data using a composite index
Diagnose the 10-million-row full scan using EXPLAIN and optimize it to read only the necessary rows.
Tuning 02 · Sorting
🔍 Product Search
Eliminate the sorting operation itself by using index sorting
Eliminates the filesort that re-sorts rows for every ORDER BY by using index-based sorting.
Tuning 03 · Join
📊 Order Statistics by Member
Fetch it all in a single pass without revisiting the original table using a covering index
Eliminates the bottleneck of re-fetching the original data on every join by using a covering index.
Tuning 04 · Grouping
⭐ Review Rating Aggregation
Index sorting for direct aggregation without a temporary table
Eliminates the temporary table created by GROUP BY using index sorting, enabling direct aggregation.
Roadmap
As a continuation of Young-han Kim's Practical Database Roadmap, this course covers how to diagnose performance issues encountered in large-scale services using execution plans and resolve them with indexes.
📚 Roadmap Structure
📺 Roadmap Learning Guide
Who is this course right for?
Job seekers and students preparing for careers in the IT field
A backend developer who encountered a slow query in a live service but is at a complete loss as to where to begin troubleshooting.
A developer who is comfortable with feature development using SQL, but lacks confidence when faced with performance issues.
Aspiring Database Administrator (DBA)
Need to know before starting?
Kim Young-han's Practical Database Fundamentals
Inflearn Verified
605,367
Learners
42,435
Reviews
9,115
Answers
5.0
Rating
27
Courses
Educator
Before: Technical Director at Woowa Bros, Kakao, SK Planet
Author: Java ORM Standard JPA Programming
My goal is to provide education so that you can become a truly practical and competent developer.
EO Interview Video
The Life of Korea's Top Developer Instructor Young-han Kim [Part 1]
The Life of Younghan Kim, Korea's Top Developer Instructor [Part 2]
Gaebalbadak - A Country Youth Becomes the King of Development
Q&A Commemorating Inflearn Reaching 200,000 Users for the First Time
Q&A Commemorating Inflearn Reaching 300,000 Users for the First Time
All
104 lectures ∙ (21hr 10min)
Course Materials:
Check out other courses by the instructor!
Explore other courses in the same field!
Limited time deal
$107,800.00
30%
$118.80