I see timescale more as an alternative option, since the OP also aksed for this. - And you're right, since Timescale is an postgresql extensions, it also has the same benefits/problems as postgresql itself in this manner.

Thanks for the recommendation of Timescale :)

Here are some more details on our future plans for clustering. We do have horizontal scale-out clustering on our roadmap and it's hard to say exactly when it will be released, but we are aiming for the 2nd half of 2018.

That said, we do often find that there multiple reasons why people ask about "clustering" or say they need scale-out:

A. Because you want to scale the amount of available storage - (we allow you to elastically add disks to scale-up the capacity on a single hypertable, have had customers scale a single hypertable to 500B rows)

B. Because you want high availability - (we support this today, via PostgreSQL streaming replication and will be documenting this further)

C. Because you want to support more concurrent queries - (supported today across primary replicas)

D. Because you want to support high ingest rates - (depending on your use case, we have users doing 100-400k rows / second)

E. Because you want to parallelize individual queries (that touch a lot of data) - (some support for parallelization today, more to come)

So we do meet the needs of many today without support for full scale-out clustering (scaling vertically, as jurgenwerk points out). If your requirements are closer to millions of rows per second inserts and storing 100s of TBs / PBs of data, we can't yet support this, but working towards it!