Hive is data warehouse infrastructure built on top of Hadoop offering tools for data ETL, a mechanism to put structures on the data, and the capability to querying and analyzing large data sets stored in Hadoop. To better understand the benefits of Hive you can check how Facebook is using Hive to deal with petabyte scale data warehouse.
Recently, John Sichi a member of the Data infrastructure team at Facebook published an article on integrating Hive and HBase. Also there is interest in having Hive work with Cassandra and this is ☞ tracked in Cassandra JIRA (nb: not sure there’s any advance on this yet though).
Hypertable-Hive integration allows Hive QL statements to read and write to Hypertable via SELECT and INSERT commands. […] Currently the Hypertable storage handler only supports external, non-native tables.
Somehow all this work to provide a common data warehouse infrastructure on top of existing NoSQL solutions (or at least the wide-column stores which are focused on large scale datasets) seems to confirm there’s no need for a common NoSQL language.