Migrating a commercial relational database (like Oracle or SQL Server) to an open-source database (like PostgreSQL or MySQL) on AWS is a heterogeneous migration. This process involves two primary steps. First, the database schema, including tables, views, and stored procedures, must be converted from the source engine's format to the target engine's format. The AWS Schema Conversion Tool (SCT) is designed specifically for this purpose. Second, the data itself must be moved from the source to the target database. AWS Database Migration Service (DMS) is the managed service that facilitates the secure and efficient migration of the data, often with minimal downtime.

B. AWS software development kits (SDKs) are libraries for application development to interact with AWS services, not a dedicated tool for database migration.

D. AWS Systems Manager is an operational management service for infrastructure configuration and automation, not for migrating database schemas or data.

E. Amazon EMR is a managed big data platform for processing large datasets using frameworks like Spark and Hadoop, not for relational database migration.

1. AWS Database Migration Service User Guide: In the section "What is AWS Database Migration Service?"

it states

"For heterogeneous migrations

you can use the AWS Schema Conversion Tool (AWS SCT) to migrate your schema. Then

you can use AWS DMS to migrate your data." This directly confirms the combined use of both services for the described task.

2. AWS Schema Conversion Tool User Guide: The "What is the AWS Schema Conversion Tool?" section explains

"You can use the AWS SCT to convert your existing database schema from one database engine to another... After you convert your schema

you can use AWS DMS to migrate your data from your source database to your target database." This highlights the distinct roles of SCT for schema conversion and DMS for data migration.

3. AWS Whitepaper: A Practitioner’s Guide to Migrating Databases to AWS (Page 10): The section "AWS Schema Conversion Tool and AWS Database Migration Service" details the process: "For heterogeneous database migrations

you can use the AWS Schema Conversion Tool (AWS SCT) together with AWS DMS. AWS SCT converts your source database schemas and code objects to a format compatible with your target database. Then

you use AWS DMS to migrate the data."