Module 22 · Core

Hands-on: query in your browser

Real SQL on real Parquet files with DuckDB running inside the page.

In plain words

Time to try it yourself. A real query engine (DuckDB) runs inside this page, on real Parquet files. Guided tasks walk you through inspecting files and proving that skipping and pruning really happen.

Helps to take first

Inside a Parquet file

Words you'll meet

SQL Parquet Query plan Predicate pushdown

This module is in production

Here's what it will cover.

Centrepiece

Guided tasks in a DuckDB-WASM sandbox: inspect Parquet metadata, compare query plans, prove pruning works

You will understand

Reading Parquet metadata and statistics
EXPLAIN and reading query plans
Measuring projection and predicate pushdown

Formats

SandboxCheckpoints