A company is planning to migrate an Amazon RDS for Oracle database to an RDS for PostgreSQL DB instance in another AWS account. A solutions architect needs to design a migration strategy that will…

While creating a new RDS PostgreSQL instance is necessary, using AWS SCT (Choice B) to create it along with schema conversion is a more comprehensive and appropriate step for heterogeneous migrations.

The AWS Schema Conversion Tool (SCT) is essential for heterogeneous database migrations like Oracle to PostgreSQL, as it converts the source database schema and code objects (tables, views, stored procedures) into a format compatible with the target, preparing the new RDS PostgreSQL instance.

Configuring VPC peering between the VPCs in the two AWS accounts establishes secure, private network connectivity, which is crucial for migration tools like AWS DMS to communicate with both the source (in a private subnet) and target databases across accounts.

Temporarily allowing the source DB instance to be publicly accessible is a significant security risk and is unnecessary when VPC peering (Choice C) can provide secure, private connectivity.

AWS Database Migration Service (DMS) with a 'full load' task is necessary to migrate all existing data from the source Oracle database to the target PostgreSQL database, forming the initial phase of data transfer for a zero-downtime migration.

AWS DMS 'change data capture' (CDC) is critical for replicating new data created during the migration and achieving zero downtime, but the provided correct answer set implicitly prioritizes the 'full load' (E) as the core DMS action when selecting three options, assuming E represents the overall data movement capability of DMS.