At Indatify we use PostgreSQL for most of the time when dealing with data. We tried to use Cassandra, but for now it is too much of a constraint in such dynamic data environment. We put it on shelf. However, for textual data we choose Elasticsearch, because we know it and it provides full text search out of the box. Later, we will come back to Cassandra, but with more specified use case, as it requires precise data model to be predefined by query and not by structure. So, to install Elasticsearch (if running without sudo, then run from root):