◈Strata 6
Query Engines & OLAP
A dashboard that loaded in two seconds now takes thirty, and “just add an index” is no answer for an analytical query scanning a billion rows.
This stratum covers how analytical query engines actually run: parsing and planning, the optimizer and its cost model, join ordering, and vectorized columnar execution — the foundations that transfer directly to ClickHouse, Trino, and DuckDB.
What you'll learn
- Follow a query from SQL text through parse, plan, and optimize to execution
- Explain why columnar plus vectorized execution wins for analytics
- Reason about cost-based optimization and join ordering
- Build a mental model that transfers across ClickHouse, Trino, and DuckDB
Tracks & courses
Full navigation is in the sidebar. Here's what each track gives you and the courses inside it.
Query Engine Foundations
Engine-agnostic theory: execution models, MPP, optimization, joins, pushdown, memory.
Related topics
Start Query Engines & OLAP free
The first chapters of every course are free to read — no account needed.