Why I'm Building a Database From Scratch in Raw C++ (And Why I Banned the STL)

Source: Dev.to

The Problem With How I Was Learning

For a long time I was writing code that worked but I had no idea why it worked. I used abstractions, APIs, and libraries that hid everything interesting. I could build things but I couldn’t explain what was actually happening in memory, on disk, or at the hardware level. That bothered me.

What NanoDB Actually Is

NanoDB is my attempt to fix that. It is a custom storage engine I am building in phases:

• Phase 0 — Raw C++ fundamentals, no safety nets
• Phase 1 — Page Manager, raw disk I/O
• Phase 2 — Buffer Pool with LRU eviction
• Phase 3 — Heap File and Tuple layout
• Phase 4 — B+ Tree Index
• Phase 5 — Query Layer
• Phase 6 — Write Ahead Log
• Phase 7 — Concurrency with 2PL
• Phase 8 — Benchmarking and research documentation

I am currently at Phase 0. I am not going to pretend I am further along than I am.

Why Ban the STL?

Because the STL solves problems I haven’t suffered through yet. If I use std::vector before I understand dynamic memory allocation, I learn nothing about what std::vector actually does. The restriction forces me to feel the pain that the abstractions were hiding. That pain is the education.

Why Am I Writing This Now, Before Writing Code?

Accountability. And because the “why” matters as much as the “what.” I will be documenting every phase here — what I built, what broke, what I learned, and what confused me. No polished success stories. Just the ugly process.

If you are also exploring systems programming or low‑level C++, follow along. We can figure this out together.

Phase 0 starts now. ⚔️