Enabling Relational Data Services (RDS)
SA z/OS provides Relational Data Services (RDS) which are available through the INGRDS command. It provides basic access methods for SA z/OS built-in relational data tables. The syntax of the INGRDS command is similar to the API of SQL but without the full SQL language parser. However, RDS is not a full SQL and does not support all concepts of SQL. SA z/OS saves the relational data tables in VSAM files.
For fast access, the relational data tables are held in the GETMAIN storage of the NetView address space. With PTF UA54030, the relational data service tables are held in 64-bit storage. Only the control data is still stored in 31-bit storage of the NetView address space. This increases the capacity of user data stored into the RDS tables. Persistence is achieved by an algorithm that periodically saves the tables into a VSAM KSDS file with DD INGEMUGL. The tables will be restored during SA initialization when NetView is started.
Each SA z/OS agent maintains its own VSAM data file and in memory tables that only hold data associated with it. When the SA z/OS agent is down, the table data cannot be accessed.