18 Data Sharing in a Nutshell
The SDa architecture supported by the Parallel Sysplex is an adaptation of SDi,
which uses coupling facilities (CFs) to solve the problem posed by messaging for
concurrency and coherency control. High speed access to the CFs provides the
necessary controls while minimizing messaging traffic. SDa is at least as robust
as the SDi alternative for continuous availability and load balancing. Because of
the coupling efficiencies and the ability to add capacity with low granularity, SDa
offers greater flexibility for growth with excellent scalability.
DB2 data sharing exploits the SDa architecture to provide the database
infrastructure for scalable growth, continuous availability, and flexible
configuration.
2.2 Data sharing ...