When talking about Cloud SQL instances on the Google Cloud Platform usually it relates to flexible and convenient handling of MySQL. Eventually, and probably less common, someone might actually speak about PostgreSQL. However in recent times Google added a third option to the Cloud SQL service: Microsoft SQL Server.

Cloud SQL is a fully managed relational database service and is fully compatible with applications using MySQL, PostgreSQL, and SQL Server. You can connect with nearly any application, anywhere in the world. Cloud SQL automates backups, replication, and fail-over to ensure your database is reliable, highly available, and flexible to your performance needs.

The described feature-set of SQL Server on GCP lists everything needed for secure, high-available, high performance, and scalable solutions. Cloud SQL instances can be easily reached from other GCP services, including App Engine, Compute Engine, Kubernetes Engine, as well as your workstation. BigQuery is capable to query directly an existing Cloud SQL database.

References:
https://jochen.kirstaetter.name/sql-server-on-gcp/
https://jochen.kirstaetter.name/sql-server-2019-on-ubuntu/