Definition of irrigation. 1  1 : the therapeutic flushing of a body part with a stream of liquid. 2  2 : the watering of land by artificial means to foster plant growth.
Answer: To start with, Oracle Real Application Clusters (RAC) are a database system involving a configuration of multiple hosts or servers joined together with clustering software and accessing the shared disk storage structures.
For example, suppose you have the Oracle RAC environment shown in Figure 4 with multiple connections to Oracle RAC nodes: A, B, and C. As shown in the first case, connections are distributed among the nodes in an Oracle RAC system.