Implementing State Machines in PostgreSQL for Data Integrity and Advanced Analytics

This article demonstrates how to implement a finite-state machine (FSM) in PostgreSQL to manage order statuses. By creating an order events table, a state transition function, and a custom aggregate function, the author builds a system that ensures valid order state transitions and prevents invalid operations. Critically, this approach also unlocks advanced analytics capabilities, such as tracking order state history and generating daily order status reports, which is invaluable for applications with large datasets. The author uses an order management system as an example, detailing the implementation steps and showcasing how to leverage the system for data analysis. The resulting system offers both data integrity and powerful analytical tools.