VoltDB. LucidDB. LucidDB is the first and only open-source RDBMS purpose-built entirely for data warehousing and business intelligence. It is based on architectural cornerstones such as column-store, bitmap indexing, hash join/aggregation, and page-level multiversioning. Most database systems (both proprietary and open-source) start life with a focus on transaction processing capabilities, then get analytical capabilities bolted on as an afterthought (if at all). By contrast, every component of LucidDB was designed with the requirements of flexible, high-performance data integration and sophisticated query processing in mind. Moreover, comprehensiveness within the focused scope of its architecture means simplicity for the user: no DBA required. MonetDB.