Learn the advantages of scalable on-demand clusters with Oracle9i RAC. IBM and PolyServe authors introduce the computing infrastructure known as Flexible Database Clusters and illustrate with a 14-node cluster of IBM eServer? BladeCenter? running Oracle9i RAC and PolyServe cluster software. Attached to a formidable SAN configured with 206 disk drives, the cluster was tested with three database workloads. Modern Linux clusters may rival the established UNIX-based server, but are they manageable? What are the ramifications of performance and availability at the application level? What is the impact on total cost of ownership? This paper answers these questions.