Your Progress
You stand before a massive fortress.
Its walls are deep gray stone, each block carved with numbers and symbols. The fortress gates are wide open, and you can see neatly arranged corridors inside — corridors lined with rows of wooden filing cabinets, illuminated rune tags floating above them: adventurers, quests, vault_items, inventory…
You pull the last letter from your backpack, in Master Chen's handwriting.
Xiao Yang,
I hear you've already built the Magic Post Road to seven cities. The roads are open, but where do you put all the things you're carrying?
You've been collecting as you go — code, configs, logs, user data, transaction records — all stuffed into your pocket (CSV files, JSON folders, ArrayList in memory).
Your pockets aren't enough anymore, are they?
Come find me. I'm at the Data Fortress. Here, you'll learn to build a real warehouse.
You look up. Above the fortress entrance, a line of words is carved:
Data Fortress Station 5: From SQL to LSM-Tree, from Indexing to Distributed Storage
You take a deep breath and walk in. Master Chen stands in the foyer, holding a huge key — engraved on it: CREATE DATABASE.
He smiles. "I've been waiting for you."
Database & Data Systems
Prerequisites
Basic programming skills required. Familiarity with basic CRUD concepts and at least one programming language. Recommended to have read Vol 1-2. For Vol 4 (Networking), understanding the "post road" analogy is sufficient; deep protocol knowledge is not required.
Volume Structure
This volume is divided into five parts, from SQL basics to distributed data systems:
Part 1: Relational Model & SQL — Blueprint of the Warehouse
[Chapter list with links to /en/vol-05-database-and-data-systems/ch*]
Part 2: Storage & Indexing — Warehouse Shelves
[Chapter list]
Part 3: Query Execution — Warehouse Manager
[Chapter list]
Part 4: Concurrency & Transactions — Warehouse Rules
[Chapter list]
Part 5: Distributed & Ecosystem — Beyond the Fortress
[Chapter list]
Traveler's Notes
"The roads are built. Where do you put your cargo?" — Master Chen's letter
Data is one of the most valuable assets of our time. The database is the warehouse you use to manage it. Starting from a simple adventurers table, in this volume you'll build the entire warehouse — shelves, ledgers, rules, branches, all complete.