You can LISTEN/NOTIFY. Or you can use logical replication and a custom subscriber.[1] Supabase uses the latter.[2]

[1]: https://www.postgresql.org/docs/current/logical-replication....

[2]: https://github.com/supabase/realtime

One caveat about LISTEN/NOTIFY is that channels are not first-class objects, so there's no authorization associated with them, thus anyone who can login can also NOTIFY any payload to any channel.

we use this feature in Supabase, works great.

Supabase has arguably a better alternative, which uses logical replication and can be used outside of Supabase.

https://github.com/supabase/realtime

Supabase realtime (especially if you want a managed backend) or other streaming CDC setups (like Decodable, which is Flink/Debezium under the hood) are also great choices for logical replication. Streaming tech will continue to get more cost-effective and simpler to implement in the coming year(s).

I should note: I haven't used Decodable in production yet, I'm just a fan of Flink :)

There is NOTIFY [1] that might do what you are thinking of.

[1] https://www.postgresql.org/docs/current/sql-notify.html

Yes, WalEx.

Recently added the concepts of Destinations - where you can just configure it to send database change events to an Elixir module, webhook or EventRelay (the later two don't require Elixir know-how).

https://github.com/cpursley/walex?tab=readme-ov-file#destina...

Youre right, real-time is generally achieved by streaming CDC data with logical replication via a connector server to Kafka (Debezium does this) or a different queue to be picked up by consumers downstream.

Supabase does a great job of abstracting that part away with their real-time feature set