Hacker News Reader

Comment by vgt | Hacker News Reader

Both technologies are clearly very compelling to users.

This is a bit outside of my expertise, but that page mainly points out that DynamoDB supports 3 more language-specific SDKs, while lacking ACID and what appears to be native cross-region replication (through Lambda). Until recently, Datastore was coupled with AppEngine that might explain it.

Would love to hear more thoughts from you.

(work at Google Cloud)

View on HN

Datastore and BigTable looks pretty interesting, and I am having a hard time figuring out when to use which (apart from Datastore's ACID support) as both seem a good enough fit for most workloads.

Is Datastore Spanner?

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/ 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.

I don't think there's an equivalent to Bigtable anywhere. It's so badass it's not even funny - take a look at [0] - a small team of engineers took O(weeks) to build a system that clocks 56 million qps (and these aren't simple bits - 56 million FIX protocol trades and orders).

You can think of Hbase as a clone of Bigtable, if that helps. Bigtable is actually exposed through the Hbase API. /u/mbrukman here is the PM for Bigtable.

[0] https://cloudplatform.googleblog.com/2016/03/financial-servi...

Last I checked the pricing was very different; nodes for BigTable, reads/writes for Datastore. BigTable is more cost effective for large workloads, but it requires buying a minimum of three nodes, which is ~$1,500/mo total. If you're small potatoes it seems infeasible. Happy to be corrected if I misread.

Reply on news.ycombinator.com