What is the difference between Oracle clusterware and Real Application Clusters? If we have 2 servers and want to join them into a cluster why there are two separate software products?
Oracle Clusterware is the clustering software that is a component of an Oracle RAC setup. Rather than being seen as a separate software product, Clusterware is part of the software stack (which includes the OS, ASM, Oracle RDBMS) that makes up an Oracle RAC cluster/deployment. Oracle support other clustering products in a RAC environment on some operating systems.