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AWS Database Migration Service (AWS DMS)

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AWS DMS
  • User AvatarPradip
  • 13 Oct, 2025
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  • 3 Mins Read

AWS Database Migration Service (AWS DMS)

AWS Database Migration Service (AWS DMS): Simplifying Cloud Database Migrations

Introduction

In today’s data-driven world, organisations are increasingly moving their databases to the cloud to achieve scalability, cost-efficiency, and agility. However, database migration can often be complex and risky — involving downtime, data loss, or compatibility issues. Amazon Web Services (AWS) solves this challenge with its powerful tool — AWS Database Migration Service (DMS).

AWS DMS makes it easy to migrate your databases quickly and securely to AWS with minimal downtime, whether you’re moving from on-premises, another cloud, or between AWS database services.

What is AWS DMS?

AWS Database Migration Service (AWS DMS) is a fully managed service that helps you migrate your databases to AWS quickly and securely. During migration, the source database remains fully operational, minimizing downtime for applications that rely on the database.

You can migrate data to and from most widely used commercial and open-source databases, including:

  • Oracle

  • Microsoft SQL Server

  • MySQL

  • PostgreSQL

  • MariaDB

  • Amazon Aurora

  • SAP ASE (Sybase)
    and even data warehouses such as Amazon Redshift.

Key Features of AWS DMS

  1. Minimal Downtime Migration
    DMS allows your source database to stay fully operational during the migration, reducing downtime and business disruption.

  2. Heterogeneous Migrations
    Easily migrate between different database engines, e.g., Oracle to PostgreSQL or SQL Server to MySQL, using AWS Schema Conversion Tool (AWS SCT).

  3. Continuous Data Replication
    You can set up ongoing replication to keep your target database in sync with the source for real-time data migration.

  4. Secure and Managed
    DMS manages all aspects of the migration process, including failover, monitoring, and data validation, with built-in SSL encryption.

  5. Scalability and Reliability
    Being an AWS-managed service, it automatically handles scaling and fault tolerance.

How AWS DMS Works

The migration process in AWS DMS typically involves three key components:

  1. Source Database – The existing database you want to migrate (e.g., Oracle on-premises).

  2. Replication Instance – The compute resource that runs the DMS software to copy data from the source to the target.

  3. Target Database – The destination database (e.g., Amazon RDS for PostgreSQL).

Steps in Migration Process:

  1. Create a Replication Instance in AWS DMS.

  2. Configure the Source and Target Endpoints with necessary connection details.

  3. Set up Replication Tasks to define what data to move and how (full load, ongoing replication, or both).

  4. Start the migration and monitor it using AWS DMS Console or CloudWatch metrics.

Common Migration Scenarios

  • On-premises Oracle → Amazon RDS for PostgreSQL

  • SQL Server → Amazon Aurora MySQL

  • Self-managed PostgreSQL → Amazon RDS for PostgreSQL

  • Oracle → Amazon Redshift (for analytics workloads)

Benefits of Using AWS DMS

Reduced Downtime: Keep applications running during migration.
Low Cost: Pay only for the resources used during migration.
Supports Multiple Databases: Works with most commercial and open-source databases.
Automated Management: AWS handles scaling, fault tolerance, and replication.
Secure Transfers: End-to-end encryption for data in motion and at rest.

Best Practices for AWS DMS

  1. Use AWS SCT (Schema Conversion Tool) for schema conversions in heterogeneous migrations.

  2. Test Migration Thoroughly before production cutover.

  3. Monitor Performance using Amazon CloudWatch.

  4. Validate Data using AWS DMS data validation feature.

  5. Optimize Network Latency — place the replication instance close to your source or target database.

Use Case Example

Scenario:
A healthcare company wants to move from an on-premises Oracle database to Amazon RDS for PostgreSQL to reduce costs and improve scalability.

Solution:
Using AWS SCT, they convert database schema and objects. Then, they use AWS DMS for the initial data load and enable ongoing replication to keep data in sync until final cutover — achieving a smooth, low-downtime migration.

Conclusion

AWS Database Migration Service (DMS) is a game-changer for businesses seeking seamless, secure, and efficient database migration to the AWS Cloud. It removes the heavy lifting of manual data transfer, reduces downtime, and ensures business continuity.

Whether you’re modernizing your legacy systems or adopting a multi-cloud strategy, AWS DMS provides the flexibility and reliability needed to make your migration journey a success.

For Learnomate Technologies Readers

At Learnomate Technologies, we help learners and professionals understand real-world tools like AWS DMS, RDS, and Database Migration Strategies through practical training and hands-on sessions.

Stay tuned for our upcoming tutorials and video demos on Oracle-to-PostgreSQL migration using AWS DMS!

Thanks for reading. Now it’s time to turn this knowledge into action. Happy learning and see you in class or in the next blog!

Happy Vibes!

ANKUSH😎

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