Postgres CDC Migration Step by Step (2026)

Introduction to Postgres CDC Migration

Migrating Change Data Capture (CDC) to Postgres is a crucial step for many organizations. With a PostgreSQL database as a source, you can migrate data to either another PostgreSQL database. In this guide, we will walk through the Postgres CDC migration step by step, covering the core concepts, step-by-step implementation, and best practices for a successful CDC to Postgres migration.

Core Concepts / How It Works

CDC is a process that captures changes made to a database and replicates them to another database. Postgres provides a native logical replication feature that enables CDC during database migration. To use this feature, you need to configure your Postgres database as a source and set up a Confluent Cloud cluster. Here is an example of how to configure Postgres as a source:

CREATE TABLE my_table (
 id SERIAL PRIMARY KEY,
 name VARCHAR(255)
);

CREATE PUBLICATION my_publication FOR TABLE my_table;

As mentioned in the AWS DMS documentation, using a PostgreSQL database as an AWS DMS source allows you to use PostgreSQL's native logical replication feature to enable change data capture (CDC) during database migration for PostgreSQL sources.

According to A practical guide to real-time CDC with Postgres, the steps to set up real-time CDC with Postgres include confirming the PostgreSQL server is configured for generating CDC events, setting up a Confluent Cloud cluster, and setting up the Kafka Connect Postgres connector.

Here are the key benefits of using CDC with Postgres:

Real-time data replication: CDC allows for real-time data replication, ensuring that your data is up-to-date and consistent across all systems.
Improved data integrity: CDC helps to improve data integrity by capturing changes made to the database and replicating them to another database.
Reduced latency: CDC reduces latency by allowing for real-time data replication, which is critical for applications that require low-latency data processing.

Step-by-Step Implementation

To migrate CDC to Postgres, follow these steps:

Prepare your Postgres database for CDC migration by creating a new database and configuring the necessary permissions.
Configure CDC events in Postgres by creating a publication and subscribing to it.
Migrate CDC data from SQL Server to Postgres using a tool like AWS DMS.

CREATE DATABASE my_database;
GRANT ALL PRIVILEGES ON DATABASE my_database TO my_user;

CREATE PUBLICATION my_publication FOR TABLE my_table;
CREATE SUBSCRIPTION my_subscription CONNECTION 'host=localhost port=5432 user=my_user password=my_password dbname=my_database';

BEGIN;
CREATE TABLE my_table (
 id SERIAL PRIMARY KEY,
 name VARCHAR(255)
);
INSERT INTO my_table (name) VALUES ('John Doe');
COMMIT;

As outlined in SQL Server to Postgres – A Step-by-Step Migration Journey, the steps to migrate from SQL Server to Postgres include preparing the database, migrating the schema, and migrating the data.

Here are some additional considerations when migrating CDC data from SQL Server to Postgres:

Data type mapping: Ensure that the data types in your SQL Server database are compatible with the data types in your Postgres database.
Schema migration: Migrate the schema of your SQL Server database to your Postgres database, including tables, indexes, and relationships.
Data migration: Migrate the data from your SQL Server database to your Postgres database, using a tool like AWS DMS.

Real-World Example or Production Patterns

In a real-world scenario, you may need to handle CDC event failures during migration. To do this, you can use a tool like Confluent Cloud to monitor and manage your CDC events. Here is an example of how to use Confluent Cloud to handle CDC event failures:

confluent cloud cdc --bootstrap-server localhost:9092 --topic my_topic --group my_group

Additionally, you can use the following code to configure the Kafka Connect Postgres connector:

{
 "name": "postgres-connector",
 "config": {
 "connector.class": "io.debezium.connector.postgresql.PostgresConnector",
 "tasks.max": "1",
 "database.hostname": "localhost",
 "database.port": "5432",
 "database.user": "my_user",
 "database.password": "my_password",
 "database.dbname": "my_database",
 "database.server.name": "my_server"
 }
}

Here are some best practices for handling CDC event failures:

Monitor CDC events: Use a tool like Confluent Cloud to monitor CDC events and detect any failures.
Handle failures: Use a tool like Confluent Cloud to handle CDC event failures, by retrying failed events or sending notifications to administrators.
Optimize CDC configuration: Optimize the CDC configuration to minimize the likelihood of failures, by adjusting settings such as batch size and latency.

Best Practices & Gotchas

Use a tool like AWS DMS to migrate CDC data from SQL Server to Postgres.
Configure CDC events in Postgres by creating a publication and subscribing to it.
Use a tool like Confluent Cloud to monitor and manage your CDC events.
Handle CDC event failures during migration by using a tool like Confluent Cloud.
Optimize Postgres performance after CDC migration by configuring the necessary permissions and indexing.

It's also important to consider the limitations of using Postgres as a source, such as the limitations on PostgreSQL as a source outlined in the AWS DMS documentation.

Here are some additional best practices for optimizing Postgres performance:

Indexing: Create indexes on columns used in WHERE and JOIN clauses to improve query performance.
Caching: Use caching mechanisms, such as Redis or Memcached, to reduce the load on your Postgres database.
Connection pooling: Use connection pooling to reduce the overhead of creating and closing connections to your Postgres database.

FAQ

What is CDC and how does it work?

CDC is a process that captures changes made to a database and replicates them to another database. It works by using a logical replication feature that enables CDC during database migration.

How do I configure Postgres as a source for CDC migration?

To configure Postgres as a source for CDC migration, you need to create a new database and configure the necessary permissions. You can then create a publication and subscribe to it to configure CDC events.

What tools can I use to migrate CDC data from SQL Server to Postgres?

You can use a tool like AWS DMS to migrate CDC data from SQL Server to Postgres.

How do I handle CDC event failures during migration?

You can use a tool like Confluent Cloud to handle CDC event failures during migration. Confluent Cloud provides a way to monitor and manage your CDC events, and handle any failures that may occur.

What are some best practices for optimizing Postgres performance after CDC migration?

Some best practices for optimizing Postgres performance after CDC migration include configuring the necessary permissions and indexing, as well as monitoring and managing your CDC events.

How do I troubleshoot common issues during CDC migration?

To troubleshoot common issues during CDC migration, you can use tools like Confluent Cloud to monitor and manage your CDC events, and handle any failures that may occur. You can also refer to the AWS DMS troubleshooting guide for more information.

What are some common pitfalls to avoid during CDC migration?

Some common pitfalls to avoid during CDC migration include not configuring the necessary permissions, not monitoring and managing CDC events, and not optimizing Postgres performance after migration.

Conclusion

In conclusion, Postgres CDC migration step by step is a crucial step for many organizations. By following the steps outlined in this guide, you can successfully migrate CDC to Postgres and ensure that your data is replicated correctly. For more information on Postgres and CDC, check out How PlayStation Network Is Built: A System Design Breakdown (Including Its Kubernetes Outages) and What is Docker and How It Works.

Additionally, here are some key takeaways from this guide:

CDC is a process that captures changes made to a database and replicates them to another database.
Postgres provides a native logical replication feature that enables CDC during database migration.
Use a tool like AWS DMS to migrate CDC data from SQL Server to Postgres.
Configure CDC events in Postgres by creating a publication and subscribing to it.
Use a tool like Confluent Cloud to monitor and manage your CDC events.