You must migrate a 2 TB relational database to GCP with minimal application refactor and lowest operating cost. Which storage/service should you choose?

Cloud SQL is the best choice for migrating a 2 TB relational database to GCP with minimal application refactor and lowest operating cost. As a fully managed relational database service, Cloud SQL supports popular engines like PostgreSQL, MySQL, and SQL Server, making it highly compatible with existing relational schemas and SQL queries. This minimizes refactoring effort. For a 2TB database, Cloud SQL offers a cost-effective solution compared to other options, especially considering its managed nature which reduces operational overhead. Cloud Spanner is a globally distributed, strongly consistent relational database, but it's designed for petabyte-scale data and high global availability, making it an overkill and more expensive for a 2 TB database. Cloud Bigtable is a wide-column NoSQL database, suitable for analytical workloads and large-scale time-series data, not a relational database, requiring significant application refactoring. Cloud Firestore is a NoSQL document database, ideal for mobile, web, and serverless applications, but also requires schema changes and refactoring for a relational database migration.