--- title: 'Replicate to another Postgres database using Logical Replication' description: 'Example to setup logical replication using publish-subscribe to a Postgres database outside of Supabase' footerHelpType: 'postgres' --- For this example, you will need: - A Supabase project - A Postgres database (running v10 or newer) You will be running commands on both of these databases to publish changes from the Supabase database to the external database. 1. Create a `publication` on the **Supabase database**: ```sql CREATE PUBLICATION example_pub; ``` 2. Also on the **Supabase database**, create a `replication slot`: ```sql select pg_create_logical_replication_slot('example_slot', 'pgoutput'); ``` 3. Now connect to your **external database** and subscribe to the `publication` This needs a **direct** connection (not a Connection Pooler) to your database and you can find the connection info in the [**Connect** panel](/dashboard/project/_?showConnect=true) in the `Direct connection` section. You will also need to ensure that IPv6 is supported by your replication destination (or you can enable the [IPv4 add-on](/docs/guides/platform/ipv4-address)) If you would prefer not to use the `postgres` user, then you can run `CREATE ROLE WITH REPLICATION;` using the `postgres` user. ```sql CREATE SUBSCRIPTION example_sub CONNECTION 'host=db.oaguxblfdassqxvvwtfe.supabase.co user=postgres password=YOUR_PASS dbname=postgres' PUBLICATION example_pub WITH (copy_data = true, create_slot=false, slot_name=example_slot); ``` For projects running Postgres 17+, it is possible to subscribe to a [Read Replica](/docs/guides/platform/read-replicas) by using your Read Replica's connection string. `create_slot` is set to `false` because `slot_name` is provided and the slot was already created in Step 2. To copy data from before the slot was created, set `copy_data` to `true`. 4. Now we'll go back to the Supabase DB and add all the tables that you want replicated to the publication. ```sql ALTER PUBLICATION example_pub ADD TABLE example_table; ``` 5. Check the replication status using `pg_stat_replication` ```sql select * from pg_stat_replication; ``` You can add more tables to the initial publication, but you're going to need to do a REFRESH on the subscribing database. See https://www.postgresql.org/docs/current/sql-alterpublication.html