Hbase

Hbase – Hadoop Wiki
Just as Google’s [WWW] Bigtable leverages the distributed data storage provided by the [WWW] Google File System, HBase provides Bigtable-like capabilities on top of Hadoop Core. Data is organized into tables, rows and columns. An Iterator-like interface is available for scanning through a row range (and of course there is the ability to retrieve a column value for a specific key). Any particular column may have multiple versions for the same row key.