That's a bit strong. Like most of engineering, it depends. Postgres is a good solution if you only have maybe 100k QPS, the locks are logically (if not necessarily fully physically) partially independent, and they aren't held for long. Break any of those constraints, or add anything weird (inefficient postgres clients, high DB load, ...), and you start having to explore either removing those seeming constraints or using other solutions.
Ok fair; I'm not really talking about postgres (the link i shared uses mysql). I'm saying that creating a ticket server that just issues and persists unique tokens, is a way to provide coordination between loosely coupled applications.
That's a bit strong. Like most of engineering, it depends. Postgres is a good solution if you only have maybe 100k QPS, the locks are logically (if not necessarily fully physically) partially independent, and they aren't held for long. Break any of those constraints, or add anything weird (inefficient postgres clients, high DB load, ...), and you start having to explore either removing those seeming constraints or using other solutions.