A financial institution needs to migrate a critical, high-transactional database (20 TB) from an on-premises Oracle Exadata cluster to AWS. The migration must achieve near-zero downtime and maintain data consistency throughout the process. After migration, the database needs to scale elastically and be highly available. Which AWS service and strategy should be used to meet these requirements?
- AUtilize AWS DataSync to transfer database files to Amazon EBS volumes, then attach to an EC2 instance.
- BManually export data to S3, then import into an Amazon DynamoDB table with on-demand capacity.
- CUse AWS Database Migration Service (DMS) with Change Data Capture (CDC) to migrate data, then cut over to Amazon RDS for Oracle as the target.
- DPerform a full database dump/restore using AWS Snowball Edge to transfer data, then import into an Amazon EC2 instance running Oracle.
Show answer & explanationAnswer & explanation
Correct answer: C. Use AWS Database Migration Service (DMS) with Change Data Capture (CDC) to migrate data, then cut over to Amazon RDS for Oracle as the target.
AWS DMS with CDC is specifically designed for heterogeneous or homogeneous database migrations with minimal downtime and continuous replication, ensuring data consistency. Amazon RDS for Oracle provides the managed service benefits of scalability, high availability, and automated backups for the target database.
Why the other options are wrong
- A. AWS DataSync is for file or object transfer, not for live, transactional database migration with CDC, and attaching raw database files to EBS/EC2 does not provide the managed database benefits of RDS.
- B. Migrating a relational Oracle database to a NoSQL DynamoDB table would require a complete re-architecture (refactor) of the application, which is a modernization strategy, not a direct migration, and is outside the scope of maintaining the existing database structure for a direct migration.
- D. Snowball Edge for a full dump/restore would incur significant downtime during the restore phase and would not meet the near-zero downtime requirement. EC2 for Oracle requires self-management, not fully leveraging AWS managed services for scalability and HA.
AWS Database Migration Service (DMS)
A cloud service that helps migrate relational databases, data warehouses, NoSQL databases, and other types of data stores to AWS quickly and securely. It supports both homogeneous and heterogeneous migrations.
- Supports continuous data replication with Change Data Capture (CDC).
- Minimizes downtime during database migrations.
- Can migrate to and from various database engines including Oracle, SQL Server, MySQL, PostgreSQL, MongoDB, etc.
Memory trick: DMS for Databases, DataSync for Files, Snowball for Bulk.