One of the most challenging parts of using the cloud is to choose the right product. Often, the cloud vendors, in this case, Google Cloud, will provide two or more services that seem to provide exactly the same functionalities.
Cloud SQL and Cloud Spanner are in that category. Both services allow to store and interrogate data with SQL, both are fully managed, and both provide ACID transactions – no drugs involved.
You should choose Cloud SQL when:
- You need a PostgreSQL, MySQL, or SQL server database engine
- Your database is smaller than 30TB in size
- You would rather not spend a fortune for your database - Cloud SQL pricing
You should choose Cloud Spanner.
- You need the data to be available all over the world in a consistent manner – Globally distributed, like Cloud Storage
- You have more than 30TB of data to read from
- You have a healthy budget - Pricing
I hope this help.
PS: For additional information go to Cloud SQL and Cloud Spanner.
PS2: For even more details: Google Cloud Professional Architect