Querying multiple tables 

Query multiple tables by using the shards parameter.

To map multiple Cassandra tables to a single Solr core, use the Solr HTTP API. Specify multiple tables using the shards parameter. For example:
http://host:port/solr/keyspace1.cf1/select?q=*:*&shards=
  host:port/solr/keyspace1.cf1,host:port/solr/keyspace2.cf2

Using the Solr API, you can query multiple tables simultaneously if they have same schema.