Which solution will reduce the cost of the database with the LEAST effort?
Use AWS Database Migration Service (DMS) to migrate to an RDS for MySQL Multi-AZ database. Update the application code to use the features of MySQL that correspond to SQL Server. Update the application to use the MySQL port.
Use AWS Database Migration Service (DMS) to migrate to an RDS for PostgreSQL Multi-AZ database. Turn on the SQL_COMPAT optional extension within the database to allow the required features. Update the application to use the PostgreSQL port.
Use AWS Database Migration Service (DMS) to migrate to an RDS for SQL Server Single-AZ database. Update the application to use the new database endpoint.
Use AWS Database Migration Service (DMS) to migrate the database to Amazon Aurora PostgreSQL. Turn on Babelfish for Aurora PostgreSQL. Update the application to use the Babelfish TDS port.
Explanations:
Migrating to RDS for MySQL would require significant changes to the application code due to differences in SQL syntax, stored procedures, and protocol handling between SQL Server and MySQL. This approach involves substantial effort and does not ensure minimal changes or compatibility.
Although PostgreSQL has the SQL_COMPAT extension, it lacks full compatibility with SQL Server’s T-SQL and SQL Server Wire Protocol, requiring application code changes. This would not provide minimal effort or seamless migration for SQL Server-specific features.
Migrating to a Single-AZ RDS for SQL Server would reduce costs but compromises high availability, which is a requirement for the application. Thus, this option does not meet the availability criteria.
Migrating to Amazon Aurora PostgreSQL with Babelfish provides SQL Server compatibility, supporting T-SQL, stored procedures, and SQL Server Wire Protocol. Babelfish minimizes required code changes, reduces costs, and maintains Multi-AZ high availability.
If I’m correct, the answer is:
Use AWS Database Migration Service (DMS) to migrate the database to Amazon Aurora PostgreSQL. Turn on Babelfish for Aurora PostgreSQL. Update the application to use the Babelfish TDS port.