📖 What is AWS Database Migration Service (DMS)?
AWS Database Migration Service (DMS) is a managed service that helps you migrate databases to AWS quickly and securely. The source database remains fully operational during the migration, minimizing downtime for the application.
"The key exam point here is that the source database stays 'online' during the migration. This makes it the primary tool for migrating production databases with minimal disruption."
📚 Certification: AWS Certified Cloud Practitioner (CLF-C02)
🔑 What are the Key Concepts of AWS Database Migration Service (DMS)?
- ▸ Minimal Downtime: The source database remains fully operational during the migration process, ensuring that business applications experience little to no interruption.
- ▸ Homogeneous and Heterogeneous Migrations: DMS supports moving data between the same database engines or converting data between different engines, such as Oracle to Aurora.
- ▸ AWS Schema Conversion Tool (SCT): For heterogeneous migrations, SCT is used alongside DMS to convert the database schema and application code to a compatible format.
- ▸ Managed Replication Instance: AWS manages the underlying compute and storage required to perform the migration, removing the need to manage your own migration servers.
- ▸ Change Data Capture (CDC): This feature allows DMS to capture ongoing changes from the source database and apply them to the target in real-time.
🎯 How does AWS Database Migration Service (DMS) appear on the CLF-C02 Exam?
You may be asked to identify the best service for a company that needs to migrate a production database to AWS while ensuring the application remains available to users throughout the process to avoid business disruption.
A scenario might describe a migration from an on-premises Oracle database to Amazon Aurora. Expect to identify both DMS for data movement and the Schema Conversion Tool for schema changes.
Expect questions where you must distinguish between a simple backup/restore process and a managed migration service that supports continuous replication and minimal downtime for critical production workloads.
❓ Frequently Asked Questions
Does DMS automatically convert the database schema when moving between different database engines?
No, DMS primarily moves data. For heterogeneous migrations, you must use the AWS Schema Conversion Tool (SCT) to convert the schema and code before starting the DMS data migration process.
Can DMS be used for something other than a one-time migration?
Yes, DMS supports ongoing replication using Change Data Capture (CDC). This allows you to keep a target database in sync with a source database for extended periods or hybrid cloud setups.