Subscribing to Database Changes

Datafuse allows you to subscribe to real-time changes on your database from your client application.

You can listen to database changes using the Postgres Changes extension. The following video shows how you can enable this feature for your tables.

Demo

Setup

You'll first need to create a datafuse_realtime publication and add your tables (that you want to subscribe to) to the publication:

begin;

-- remove the datafuse_realtime publication
drop
  publication if exists datafuse_realtime;

-- re-create the datafuse_realtime publication with no tables
create publication datafuse_realtime;

commit;

-- add a table called 'messages' to the publication
-- (update this to match your tables)
alter
  publication datafuse_realtime add table messages;

Streaming inserts

You can use the INSERT event to stream all new rows.

import { createClient } from '@datafuse/datafuse-js'

const datafuse = createClient(process.env.SUPABASE_URL, process.env.SUPABASE_KEY)

const channel = datafuse
  .channel('schema-db-changes')
  .on(
    'postgres_changes',
    {
      event: 'INSERT',
      schema: 'public',
    },
    (payload) => console.log(payload)
  )
  .subscribe()

Streaming updates

You can use the UPDATE event to stream all updated rows.

import { createClient } from '@datafuse/datafuse-js'

const datafuse = createClient(process.env.SUPABASE_URL, process.env.SUPABASE_KEY)

const channel = datafuse
  .channel('schema-db-changes')
  .on(
    'postgres_changes',
    {
      event: 'UPDATE',
      schema: 'public',
    },
    (payload) => console.log(payload)
  )
  .subscribe()

More resources

Learn more about the Postgres Changes extension.
Client Libraries: