MySQL Learning Lab

An interactive playground for learning MySQL performance, features, and best practices.
Each lab demonstrates a specific concept using Java + Dockerized MySQL.

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🚀 Quickstart

git clone <repo-url>
cd mysql-lab
docker compose up -d    # start MySQL in Docker
mvn compile

• MySQL runs inside Docker (labdb database, user: labuser / pass: labpass).
• Java programs connect to it using JDBC and measure performance.

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📚 Labs

✅ Indexing

• Good Index Benchmark High-cardinality column (name) → index makes queries much faster.
• Bad Index Benchmark Low-cardinality column (department) → index actually slows queries down.

Run:

# Good index demo
mvn exec:java -Dexec.mainClass="IndexBenchmark"

# Bad index demo
mvn exec:java -Dexec.mainClass="BadIndexBenchmark"

📖 Indexing README

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🔜 Coming Soon

I'll be adding labs for:

• Joins & query plans
• Transactions & isolation levels
• Deadlocks & locks
• Stored procedures
• Partitioning
• Replication basics

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🏗️ Structure

mysql-lab/
├── docker-compose.yml   # MySQL in Docker
├── pom.xml              # Maven project setup
├── indexing/            # Index-related lab
│   ├── IndexBenchmark.java
│   ├── BadIndexBenchmark.java
│   └── README.md
└── ... more labs coming soon ...

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🧠 What You’ll Learn

• How to measure and interpret query performance.
• When and why indexes help (or hurt).
• How to read MySQL EXPLAIN plans.
• Core concepts of MySQL internals step by step.