Add polling option for subscriptions as a fallback when Postgres LISTEN / NOTIFY is unsupported

[slashdotdash]

In certain environments Postgres’ built-in notification mechanism (LISTEN / NOTIFY) is not supported. This might be due to using an external connection pool, such as pgbouncer, or limitations of a managed Postgres service.

To support these environments a fallback polling option could be provided where newly appended events are queried at a regular interval and published to subscribers. This would add additional latency to subscribers dependent upon the pool interval, which should be configurable. A short polling interval would reduce latency but add load to the database.

[esse]

any progress here? We're using commanded together with pgbouncer and it would make our life so much better!