Convert the schema - AWS Prescriptive Guidance

Convert the schema

One of the key tasks during the database migration is to migrate your schema from the source database engine to the target database engine. If you rehost or replatform, your database engine won’t change. This is referred to as a homogeneous database migration, and you can use your native database tools to migrate the schema.

However, if you are rearchitecting your application, schema conversion might require more effort. In this case, you will be doing a heterogeneous database migration, where your source and target database engines will be different. Your current database schema may be using packages and features that cannot be directly converted to the target database engine. Some features might be available under a different name. Therefore, converting the schema requires a good understanding of your source and target database engines. This task can be challenging, depending on the complexity of your current schema.

AWS provides two resources to help you with schema conversion: AWS Schema Conversion Tool (AWS SCT) and migration playbooks.

AWS SCT

AWS SCT is a free tool that can help you convert your existing database from one engine to another. AWS SCT supports a number of source databases, including Oracle, Microsoft SQL Server, MySQL, Sybase, and IBM Db2 LUW. You can choose from target databases such as Aurora MySQL and Aurora PostgreSQL.

AWS SCT provides a graphical user interface that directly connects to the source and target databases to fetch the current schema objects. When connected, you can generate a database migration assessment report to get a high-level summary of the conversion effort and action items. The following screen illustration shows a sample database migration assessment report.


      Sample database migration assessment report from AWS SCT

With AWS SCT you can convert the schema and deploy it into the target database directly, or you can get SQL files for the converted schema. For more information, see Using the AWS Schema Conversion Tool User Interface in the AWS documentation.

Migration playbooks

Although AWS SCT converts many of your source objects, some aspects of conversion require manual intervention and adjustments. To help with this task, AWS provides migration playbooks that detail incompatibilities and similarities between two databases. For more information about these playbooks, see AWS Database Migration Service resources on the AWS website.