DHT can certainly support range queries by broadcast and merge. The keyword in the context though is efficiently. Scalaris not a typical Dynamo like DHT. It's based on Chord, so it's possible support range scan with O(logn) metadata RPCs (n is number of nodes.) per query, which I wouldn't call efficient as these RPCs are expensive in that they not very cachable (nature of the DHT, unless the range query is exactly the same.) Typical Bigtable implementation can easily cache portion of metadata with clients and resulting 0 metadata RPC in many cases.