HadoopDB is a hybrid of MapReduce and DBMS technologies, designed to meet the growing demand of analyzing massive datasets on very large clusters of machines. Our previous work has shown that HadoopDB approaches parallel databases in performance and still yields the scalability and fault tolerance of MapReduce-based systems. In this demonstration, we focus on HadoopDB’s flexible architecture and versatility with two real world application scenarios: a semantic web data application for protein sequence analysis and a business data warehousing application based on TPCH. The demonstration offers a thorough walk-through of how to easily build applications on top of HadoopDB. Categories and Subject Descriptors H.2.4 [Database Management]: Systems General Terms Design, Performance