Many migration strategies and approaches run in multiple phases that can last from a few weeks to several months. During this time, you can experience delays because of patching or upgrades in the source Oracle DB instances that you want to migrate to PostgreSQL DB instances. To avoid this situation, we recommend that you incrementally migrate the remaining Oracle database code to PostgreSQL database code.
This pattern provides an incremental migration strategy with no downtime for a multi-terabyte Oracle DB instance that has a high number of transactions performed after your initial migration and that must be migrated to a PostgreSQL database. You can use this pattern’s step-by-step approach to incrementally migrate an Amazon Relational Database Service (Amazon RDS) for Oracle DB instance to an Amazon RDS for PostgreSQL DB instance without signing in to the Amazon Web Services (AWS) Management Console.
The pattern uses Oracle SQL Developer to find the differences between two schemas in the source Oracle database. You then use AWS Schema Conversion Tool (AWS SCT) to convert the Amazon RDS for Oracle database schema objects to Amazon RDS for PostgreSQL database schema objects. You can then run a Python script in the Windows Command Prompt to create AWS SCT objects for the incremental changes to the source database objects.
Note: Before you migrate your production workloads, we recommend that you run a proof of concept (PoC) for this pattern's approach in a testing or non-production environment.
