With the release of PostgreSQL 9.3, it let’s us do some really cool things with writable foreign tables. BigSQL just release a Hadoop Foreign Data Wrapper that is writable into HDFS files and Hbase tables. The Hbase integration allows for full SELECT, INSERT, UPDATE and DELETE syntax through PostgreSQL and the HDFS integration allows for SELECT and INSERT.
The HadoopFDW is released under the PostgreSQL license and can be found here.