Database Migration Service for Oracle to AlloyDB for PostgreSQL FAQ

What is Database Migration Service?
Database Migration Service is a service that makes it easier for you to migrate your data to Google Cloud. Database Migration Service helps you lift and modernize your Oracle workloads into AlloyDB for PostgreSQL.
Which sources are supported?
  • Oracle 11g, Version 11.2.0.4
  • Oracle 12c, Version 12.1.0.2
  • Oracle 12c, Version 12.2.0.1
  • Oracle 18c
  • Oracle 19c
  • Oracle 21c
Which destinations are supported?
  • AlloyDB for PostgreSQL 14, 15
Which networking methods are used?
To create a migration in Database Migration Service, connectivity must be established so that Database Migration Service can connect to both the source and the destination database. There are a variety of methods supported. Choose the one that works best for the specific workload.

Source connectivity:

For a list of supported source connectivity methods, see Source connectivity.

Destination connectivity:

Use Private Service Connect to establish private connectivity to the AlloyDB for PostgreSQL destination database.

What are the known limitations?
See Known limitations.
Can I connect to the destination AlloyDB for PostgreSQL instance using a private IP address without the Private Service Connect resources?
No. Database Migration Service leverages Private Service Connect to connect privately to the destination database, and expects a service attachment as input.
Can I use Database Migration Service to create read replicas for my Oracle database in AlloyDB for PostgreSQL?
The continuous migration from Oracle to AlloyDB for PostgreSQL in Database Migration Service is eventually consistent, meaning that Database Migration Service doesn't replicate each transaction as it happens.

The migration brings in data from multiple tables, running both change data capture (CDC) and the backfill of data in parallel. The order in which data is loaded into the destination isn't strictly guaranteed, but will re-align with the source after writes on the source are stopped and the migration buffer is cleared.