(1) A collection of one or more DB2 for z/OS subsystems that directly access and change the same data while maintaining data integrity.
(2) In IMS, the components involved in sysplex data sharing. Among the components are the sharing IMS subsystems, the IRLMs they use, the IRLM, OSAM, and VSAM structures in the coupling facility, and a single set of DBRC RECONs.