Use the PostgreSQL CDC (Change Data Capture) Connector to get data from PostgreSQL into Decodable. The PostgreSQL CDC Connector is powered by Debezium and able to extract and send change events (INSERTS, UPDATES, and DELETES) through Decodable.

If you are looking for instructions on how to send data from Decodable into Postgres, see PostgreSQL in the Connect to a data destination chapter.

Overview


Connector name	`postgres-cdc`
Type	`source`
Delivery guarantee	exactly once

Prerequisites

Before you can get data from PostgreSQL, the following requirements must be met:

Your Postgres database must be publicly accessible. Decodable uses the username and password provided during connection creation to authenticate to the database.
Your Postgres database must have the logical decoding feature enabled, which provides the ability to stream data changes to external consumers. The way you enable this feature depends on the Cloud environment that you are running Postgres in. If you are running Postgres in See Setting up Postgres from the Debezium documentation for more information.
Your Postgres database user must have sufficient permissions to create PostgreSQL publications. See Setting privileges to enable Debezium to create PostgreSQL publications when you use pgoutput from the Debezium documentation for more information.
Have your Postgres database information handy. This includes the hostname of your database, the name of the database, the name of the database table, and the username and password used to login to the database. You will need to provide this information as part of connection creation.

For video guidance on completing these prerequisites, see the Decodable YouTube video How to Enable Change Data Capture with Postgres on Amazon RDS to learn how to prepare a Postgres database on Amazon RDS that can connect and send CDC records to Decodable.

Steps

Follow these steps to get data from PostgreSQL into Decodable. These steps assume that you are using the Decodable web interface. However, if you want to use the Decodable CLI to create the connection, you can refer to the Property Name column for information about what the underlying property names are.

From the Connections page, select PostgreSQL CDC and complete the following fields.

UI Field	Property Name in the Decodable CLI	Description
Connection Type	N/A	Select Source to use this connector to get data into Decodable.
Host	`host`	The host where the PostgreSQL database can be reached. For example, `postgres-server`.
Port	`port`	Optional. The port where the PostgreSQL database can be reached. Defaults to `5432`.
Database	`database-name`	The name of the database.
Schema	`schema-name`	The name of the schema containing the table that you want to receive data from. Defaults to `public`.
Table Name	`table-name`	The name of the database table for the connection.
Username	`username`	The username to use to authenticate to PostgreSQL.
Password	`password`	The password associated with the username. This must be provided as a secret resource. If you are using the Decodable CLI, run `decodable secret list` to view available secrets or `decodable secret --help` for help with creating a new secret. Note: For security purposes, Decodable will never display secret values in plaintext. You can manage which users have permissions to create, delete, or modify secrets in the Access Control management view. See Manage Roles, Groups, and Permissions for more information.
Decoding Plugin Name	`decoding.plugin.name`	Optional. The plugin to use for reading data from the database. Defaults to `pgoutput`.

Select the stream that you’d like to connect to this connector. Then, select Next.
Define the connection’s schema. Select New Schema to manually enter the fields and field types present or Import Schema if you want to paste the schema in the form of an Avro or JSON array.
1. The stream's schema must match the schema of the data that you plan on sending through this connection.
2. You must designate one or more fields to use as a primary key. A primary key is a field that contains a value that can be used to uniquely identify each row in a table. To specify a primary key, you must first explicitly tell Decodable that the type is not null explicitly by entering: <type> NOT NULL. For example: BIGINT NOT NULL.
3. For more information about Change Data Capture, change streams, or creating a stream, see the following pages:
  - About Change Data Capture and Change Streams.
  - Create a Stream.
Select Next when you are finished providing defining the connection’s schema.
Give the newly created connection a Name and Description and select Save.