A heterogeneous migration moves data between different database technologies.
The database engine of the source, such as Oracle differs from the database
engine of the destination, such as PostgreSQL.

Heterogeneous migrations are more complex than homogeneous migrations due to
differences in schema structure, data types, and metadata components between the
source database and the destination database. Database Migration Service provides tools,
such as Gemini-assisted schema and code conversion, that help you
convert the schema and objects from your source database into a format that is
compatible with your destination database.

Heterogeneous migrations use replication based on Change Data Capture (CDC) to
process ongoing changes.

For more information, see supported scenarios.

## Supported scenarios

Database Migration Service supports the following heterogeneous migrations:

- [Migrate from Oracle to Cloud SQL for PostgreSQL](https://docs.cloud.google.com/database-migration/docs/oracle-to-postgresql/scenario-overview.md.txt)
- [Migrate from Oracle to AlloyDB for PostgreSQL](https://docs.cloud.google.com/database-migration/docs/oracle-to-alloydb/scenario-overview.md.txt)
- [Migrate from SQL Server to Cloud SQL for PostgreSQL](https://docs.cloud.google.com/database-migration/docs/sqlserver-to-csql-pgsql/scenario-overview.md.txt)
- [Migrate from SQL Server to AlloyDB for PostgreSQL](https://docs.cloud.google.com/database-migration/docs/sqlserver-to-alloydb/scenario-overview.md.txt)