HadoopDB is:

1. A hybrid of DBMS and MapReduce technologies that targets analytical workloads
2. Designed to run on a shared-nothing cluster of commodity machines, or in the cloud
3. An attempt to fill the gap in the market for a free and open source parallel DBMS
4. Much more scalable than currently available parallel database systems and DBMS/MapReduce hybrid systems.
5. As scalable as Hadoop, while achieving superior performance on structured data analysis workloads

Looks very hot. Can’t wait to get into that VLDB paper on this page.