How Query Engines Think: The Tradeoffs Behind Every Data System

This article provides a comprehensive overview of the nine fundamental design decisions every query engine must make, including storage layout (row vs. column), disk organization, indexing, query optimization, execution models, memory management, partitioning, join algorithms, and concurrency control. It uses examples from systems like PostgreSQL, ClickHouse, DuckDB, and Dremio to illustrate how each choice optimizes for specific workloads while creating tradeoffs. The content is technical and focused on database internals, making it highly relevant to IT and technology professionals interested in data systems, software engineering, and system design.