Google Cloud Bigtable vs Google Cloud Datastore

Question

What is the difference between Google Cloud Bigtable and Google Cloud Datastore / App Engine datastore, and what are the main practical advantages/disadvantages? AFAIK Cloud

Answer 1

If you read papers, BigTable is this and Datastore is MegaStore. Datastore is BigTable plus replication, transaction, and index. (and is much more expensive).