DuckLake: The Definitive Guide

Chapter 3. DuckLake Architecture Deep Dive

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This chapter explores the internal design of DuckLake and the reasoning behind its architecture. We will examine how data is written and stored, how metadata is managed, and how queries execute across the system. By the end of this chapter, you will understand how DuckLake coordinates catalog, storage, and compute components to efficiently manage analytical workloads at scale.

The Three-Component Architecture

DuckLake is built around three primary architectural components: the catalog, the storage layer, and the compute layer.

A natural question is: why three separate components instead of one unified system?

The answer lies in the principle of separation of concerns. Each component solves a fundamentally different problem, and each problem scales in different ways.

• The catalog manages metadata: table definitions, schema evolution, transaction history, and references to physical data files

• The storage layer manages the data itself: typically large, ...