> ## Documentation Index
> Fetch the complete documentation index at: https://docs.peaka.com/llms.txt
> Use this file to discover all available pages before exploring further.

# CDC - PostgreSQL Setup Documentation

> How to setup CDC PostgreSQL

## **Prerequisites**

To setup CDC between your PostgreSQL database and Peaka BI Table, you need:

* PostgreSQL version 10+
* PostgreSQL administrative permissions.

## **Setup Instructions**

### Setting up permissions

Create a database user for Peaka's exclusive use that can perform replication.

( Although, by default, superusers have the necessary **REPLICATION** and **LOGIN**roles, you can create another user that has the minimum required privileges. )

1. To provide a user with replication permissions, define a PostgreSQL role that has *at least* the **REPLICATION** and **LOGIN** permissions, and then grant that role to the user. For example:

```sql theme={null}
CREATE ROLE <role> REPLICATION LOGIN;
```

### Configure the PostgreSQL server to logical replication with the **pgoutput** plugin

1. Set the **wal\_level** parameter in your database configuration to **logical**. For a standard PostgreSQL database, do this by adding a **wal\_level = logical** line to the **postgresql.conf** file. Restart the server for this change to take effect.

2. Ensure that your **max\_replication\_slots** value is equal to or higher than the number of PostgreSQL connectors that use WAL *plus* the number of other replication slots your database uses.

3. Create a publication for your tables.

   1. If the user you provide the Peaka connection with has superuser permissions, the publication is created at start-up automatically, if it does not already exist.

   b. You can create a publication for all of your tables.

   ```sql theme={null}
   CREATE PUBLICATION <publication_name> FOR ALL TABLES;
   ```

   c. Alternatively, you can create a publication for only tables under the cached schema.

   ```sql theme={null}
   CREATE PUBLICATION <publication_name> FOR TABLES IN SCHEMA <schema_name>;
   ```

4. Create a logical replication slot (Optional)

   ```sql theme={null}
   SELECT pg_create_logical_replication_slot(<slot_name>, 'pgoutput');
   ```

   Note: since a replication slot can only be used by a single connector, it is essential to create a unique replication slot for each CDC connection.