We have lots of users(30-200 million). Each user has N(30-100) attributes. The attribute can be of type integer, text, timestamp or counter. Schema is not defined.
We are looking for a database to which we can index and retrieve(GET API) users in the most efficient way(low response time). We also have the requirement to search for users but this is out of this topic. We also need to have strong consistent and high available data.
I already know that GET API provides consistent data, but I'm not sure if Elasticsearch is the right choice for this case. We have tried Cassandra but the read performance was low(high disk IOPS).