We also have transactions [1], compound indexes [2] and multi-region replication...

We also have transactions [1], compound indexes [2] and multi-region replication [3]. I'm not sure what defines a "full-blown" database, but that much is true.

[1] https://cloud.google.com/datastore/docs/concepts/transaction...

[2] https://cloud.google.com/datastore/docs/concepts/indexes

[3] https://cloud.google.com/docs/geography-and-regions#multi-re...