Not sure how to ask this question, but as I understand google cloud SQL supports the idea of instances, which are located throughout their global infrastructure...so I can have a single database spread across multiple instances all over the world.
I have a a few geographic regions our app serves...the data doesn't really need to be aggregated as a whole and could be stored individually on separate databases in regions accordingly.
Does it make sense to serve all regions off one database/multiple instances? Or should I segregate each region into it's own database and host the data the old fashion way?
If by “scaling” you mean memory size, then you can start with a smaller instance (less RAM) and move up to a more powerful instance (more RAM) later.
But if you mean more operations per second, there is a certain max size and max number of operations that one Cloud SQL instance can support. You cannot infinitely scale one instance. Internally the data for one instance is indeed stored over multiples machines, but that is more related to reliability and durability, and it does not scale the throughput beyond a certain limit.
If you really need more throughput than what one Cloud SQL instance can provide, and you do need a SQL based storage, you’ll have to use multiple instances (i.e. completely separate databases) but your app will have to manage them.
Note that the advantages of Cloud go beyond just scalability. Cloud SQL instances are managed for you (e.g. failover, backups, etc. are taken care of). And you get billing based on usage.
(Cloud SQL team)