AWS Database Migration Service (DMS)

AWS Database Migration Service (DMS) helps you migrate databases to AWS quickly and securely. The source database remains fully operational during the migration, minimizing downtime to applications that rely on the database.

Key Features

Homogeneous Migrations: Migrate between the same database engines (e.g., Oracle to Oracle).
Heterogeneous Migrations: Migrate between different database engines (e.g., Oracle to Amazon Aurora). Requires AWS Schema Conversion Tool (SCT).
Continuous Replication: Can be used for continuous data replication (Change Data Capture - CDC).
Serverless: DMS Serverless automatically provisions and scales resources.
DMS Fleet Advisor: Automates migration planning for large fleets of databases.

Exam Tips

"Migrate Database": Answer is DMS.
"Different Database Engine": Answer is DMS + SCT (Schema Conversion Tool).
"Zero Downtime / Minimal Downtime": DMS allows the source to remain active.
"On-premises to AWS": Common use case.

Common Use Cases

Database Migration: moving an on-prem Oracle DB to Aurora PostgreSQL.
Data Replication: Replicating data to S3 for a data lake.
Development: Creating test databases from production data.