Google Cloud SQL is a managed relational database service on Google Cloud. It supports MySQL, PostgreSQL and SQL Server and is intended for organisations that want to run a database without administering servers themselves. According to the documentation, Google handles provisioning, backups, replication and high availability, while the customer manages the data and access to it. Cloud SQL is delivered only as a cloud service and forms part of the wider Google Cloud platform.
Google LLC is part of Alphabet Inc., which is headquartered in the United States. The service is therefore subject to US law such as the CLOUD Act, even when data is stored in Europe. When creating an instance the customer chooses a region; European options include Belgium, Frankfurt, the Netherlands, Paris and Warsaw, and the location cannot be changed afterwards. Google offers a Cloud Data Processing Addendum under which Google acts as processor. For a European organisation the region choice therefore matters for data residency, but not for the jurisdiction of the provider.