Inter-Process Communication (IPC)

PostgreSQL allows for a dynamic Inter-Process Communication (IPC) where each backend process can communicate with other backend processes. While PostgreSQL provides a way to signal a backend process in order to terminate it—a kind of extreme IPC—the kind of communication this section focuses on is the asynchronous event model, which is known as a channel.

Asynchronous events

PostgreSQL provides a mechanism to publish events over a channel. Subscribers can subscribe to this channel to receive these events. The whole communication process happens asynchronously.

Each event is sent over a channel, which is identified by a unique name and can have an optional payload, in the form...