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cstack/db_tutorial

★ 10,406CAudience · developerComplexity · 3/5Setup · moderate

TLDR

A guided tutorial for building a simplified SQLite-like database engine from scratch in C, teaching how databases store data on disk, parse queries, and execute them at a low level.

Mindmap

mindmap
  root((db tutorial))
    What it does
      Build a database
      Step by step
      Educational only
    Teaches
      Disk storage
      Query parsing
      B-tree structure
      File format design
    Language
      C low level
      Manual memory
    Format
      Tutorial website
      Companion code
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Code map

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Things people build with this

USE CASE 1

Learn how relational database internals work by building one yourself in C.

USE CASE 2

Understand how data is stored on disk in a B-tree structure by implementing it step by step.

USE CASE 3

Study how a query parser and executor work at the lowest level.

USE CASE 4

Build foundational systems programming knowledge through a concrete, guided project in C.

Tech stack

C

Getting it running

Difficulty · moderate Time to first run · 1h+

Requires a C compiler, the repo has minimal instructions, the tutorial website is where the actual content lives.

In plain English

This repository is a tutorial project that walks through building a simple database from scratch using the C programming language, modeled after SQLite. SQLite is one of the most widely used databases in the world: it stores data in a single local file rather than requiring a separate server process to be running. The goal of this project is educational, not practical. It does not produce a database you would use in production. It shows, step by step, how a database engine works by building a simplified one. C is a low-level programming language where you manage memory and file operations directly, without many of the conveniences higher-level languages provide. Building a database in C means grappling with the fundamentals: how records are stored on disk, how a file is structured so data can be read back efficiently, and how a simple query gets parsed and executed. Working through those problems is the point. The README in this repository is minimal by design. It points to a separate tutorial website where the actual instructional content lives, with detailed writing and code walkthroughs accompanying each step. The code in the repository is the companion implementation for those tutorial pages. If you are interested in understanding how databases work internally, this is the kind of project that makes the underlying mechanics concrete by making you build them yourself.

Copy-paste prompts

Prompt 1
I'm working through the db_tutorial C database project, explain how the B-tree storage format works and why it's used for database pages.
Prompt 2
Help me implement the row serialization step from db_tutorial in C, where records are written to fixed-size pages.
Prompt 3
I'm stuck on the cursor implementation in db_tutorial, explain how a cursor traverses a B-tree to find a specific row.
Prompt 4
Walk me through adding a simple SELECT with a WHERE clause to the db_tutorial SQLite clone in C.
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