This article explains how to migrate Microsoft SQL Server databases to Babelfish for Aurora PostgreSQL with minimal downtime using AWS Database Migration Service (DMS).

• Babelfish enables SQL Server applications to run on Aurora PostgreSQL with minimal code changes
• Three migration options: AWS DMS with Babelfish endpoint, AWS DMS with Aurora PostgreSQL endpoint (minimal downtime), or SQL Server tools
• Minimal downtime approach uses AWS DMS with Full Load and Change Data Capture (CDC) tasks
• Requires Babelfish Compass assessment tool to evaluate T-SQL compatibility before migration
• Identity columns must be converted to SERIAL datatype for CDC replication support
• Sequences must be reseeded after migration to ensure correct identity values
• Detailed 18-step migration process includes schema creation, DMS configuration, and validation
• Current limitations include no support for data validation on Babelfish endpoint and precision differences in datetime types

This guide provides a comprehensive approach to migrating SQL Server workloads to Aurora PostgreSQL while maintaining application compatibility through Babelfish.