Behind the scenes: How Database Traffic Control works

Database Traffic Control™ is a newly released feature designed to mitigate and prevent database overload from unexpectedly expensive SQL queries by utilizing the capabilities of Postgres extensions and a sophisticated query management system. The feature leverages hooks in the Postgres architecture to evaluate and manage SQL query execution in real-time, integrating with the existing pginsights extension to measure query resource consumption. By employing mechanisms like static analysis and cumulative resource usage, Traffic Control can block or warn queries based on a set of configurable rules and budgets. It uses a unique leaky-bucket model to manage cumulative query costs, ensuring that high-demand periods do not overwhelm server resources. Traffic Control dynamically estimates query costs by adjusting Postgres's planner cost predictions with real-world execution data, allowing for more precise control over query initiation. This system provides developers and database administrators with enhanced tools to prioritize and regulate SQL traffic efficiently, ensuring stable database operations even under heavy loads.