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.
Rather than throwing hardware at data warehousing problems by relying on expensive clusters or specialized "appliances", the scalability offered by LucidDB's unique architecture allows you to achieve great performance using only a single off-the-shelf Linux or Windows server. Besides keeping costs down, this also minimizes maintenance and administration hassles.
Still wondering why you might want to spend time trying out LucidDB when the open-source DBMS field is already crowded with so many good horses? Use the navigation bar on the left to browse features, architecture, roadmap, and other docs to find out.