You're correct in that Datastore does provide more general transactions (Bigtable only provides single-row transactions); Datastore also provides indexing and s

You're correct in that Datastore does provide more general transactions (Bigtable only provides single-row transactions); Datastore also provides indexing and search (Bigtable, like HBase, has a single index: the row key), and Datastore is synchronously replicated cross-zone and cross-region. Datastore and Bigtable have different characteristics and use cases; see https://cloud.google.com/storage-options/ https://cloud.google.com/storage-options/ for an overview. Datastore is a document database (compare it to MongoDB), while Bigtable is a wide-column store (compare it to HBase or Cassandra). > Is Datastore Spanner? Datastore is built on Megastore, which builds on Bigtable. :-) I am the PM for Google Cloud Bigtable.