MiniDuck

A tiny educational OLAP engine built in ~700 lines of Rust. It accompanies a six-chapter tutorial on how a real columnar engine like DuckDB is put together.

Layout

Chapter	Module	Idea
1	src/storage.rs	Columnar batches over arrow2
2	src/exec.rs	Pull-based Volcano operators
3	src/expr.rs	Scalar expression trees
4	src/agg.rs	Hash aggregation with hashbrown + ahash
5	src/catalog.rs + src/planner.rs	Catalog + tiny SQL planner
6	benches/	Synthetic micro-benchmark

Run an example

cargo run --example ch1_table
cargo run --example ch2_scan
cargo run --example ch3_filter
cargo run --example ch4_agg
cargo run --example ch5_sql

Run tests

cargo test

Run the benchmark

cargo bench --bench tpch_lite

A like-for-like comparison against duckdb is described in chapter 6 of the tutorial, but the dependency is intentionally omitted from Cargo.toml so that this teaching crate stays light.