The best alternatives to MemSQL are Google Cloud Platform, Unbounded, and Bytebase. If these 3 options don't work for you, we've listed a few more alternatives below.
What do you think of MemSQL?
Tanka— Tanka = Slack + Glean, built for fast-growing startups.
Store any unstructured JSON data without constraints on primary keys, property names or embedded objects. Map, reduce, and receive query results to your webhooks. Any valid Javascript works as a query, ending limitations imposed by proprietary query languages.