e72bfd15_Cassandra_vs_HBase___WhyNosql__Cassandra
[HBase] Concept of Table exists. Each table has it's own key space. This was a big win for us. You can add and remove table as as easily as a RDBMS. [Cassandra] 
Lacks concept of a Table. All the documentation will tell you that it's not common to have multiple keyspaces. That means you have to share a key space in a cluster. Furthermore adding a keyspace requires a cluster restart!
Cassandra vs HBase | WhyNosql
Cassandra