Baradb/reddit_post_draft.md

r/nim — [Showcase] BaraDB: A database engine written from scratch in Nim

Hey r/nim! I wanted to share a project I've been working on for the past several months.

BaraDB is a multimodal database engine written entirely in Nim — no C/C++ dependencies, no PostgreSQL, no external services. Just Nim.

What is it?

A single-binary (~3.3MB) database that combines:

• Document/KV storage — LSM-Tree with WAL, bloom filters, SSTable compaction
• SQL-compatible query language — BaraQL with SELECT/INSERT/UPDATE/DELETE, JOINs, GROUP BY, CTEs, indexes
• Graph engine — BFS, DFS, Dijkstra, PageRank, Louvain communities
• Vector search — HNSW index with SIMD-optimized distance metrics
• Full-text search — BM25 + TF-IDF with stemming (EN/BG/DE/RU)
• Columnar engine — RLE, dictionary encoding, batch operations
• Wire protocol — binary protocol + HTTP/REST + WebSocket + JWT auth
• 4 client SDKs — Nim, Python, JavaScript, Rust

Architecture

Client Layer     → Binary / HTTP / WebSocket
Query Layer      → Lexer → Parser → AST → IR → Optimizer → Codegen
Execution Engine → Document / Graph / Vector / Columnar / FTS
Storage          → LSM-Tree / B-Tree / WAL / Bloom / mmap
Distributed      → Raft / Sharding / Replication (core logic)

Some numbers

• ~15,000 lines of Nim
• 269 tests, all passing
• Green CI (GitHub Actions)
• Benchmarks: B-Tree point lookup ~1.5M ops/s, LSM-Tree writes ~580K ops/s

What's actually working vs. what's WIP

Solid:

• SQL parser & executor (JOINs, GROUP BY, subqueries, CTEs, indexes)
• MVCC transactions, deadlock detection
• LSM-Tree storage with background compaction
• B-Tree indexes with range scans
• Wire protocol + clients

In-memory / proof-of-concept:

• Graph, Vector, FTS, Columnar engines (serialization exists, persistence optional)
• Distributed layer (Raft core logic is there, network transport is stubbed)

Still rough:

• Recursive CTE execution
• Some edge-case query optimizations

Why Nim?

Nim's metaprogramming, zero-cost abstractions, and C-like performance made it perfect for building a storage engine without drowning in C++ complexity. The binary compiles to a single static executable — deployment is just scp.

Repo

github.com/katehonz/barabaDB

Feedback welcome — especially from anyone who's built storage engines before. I know there's a lot left to do, but I'm proud of how far it's come.