CA OPS/MVS implements its relational tables as a set of global variables. One global variable stores one row of a relational table, which you can access only through SQL statements.
The CA OPS/MVS product keeps Relational Data Framework global variables in a data-in-virtual (DIV) data set. Storing the variables in this way speeds up processing and allows the Relational Data Framework to operate in a time-sensitive environment. To have a permanent database for these variables, you must include the SYSCHK1 DD statement in your CA OPS/MVS startup procedure.
When CA OPS/MVS updates a row in a relational table, the change takes place in main storage, and occurs quickly. To ensure that the updated information remains safe if the system fails without warning, the representation of the relational table in main storage is periodically flushed to the DASD image of the DIV data set. However, updates that have not been saved to DASD can be lost if the system fails. By default, the flush to DASD occurs every 15 seconds (the system administrator can adjust this interval), so data that has changed in 15 seconds of failure may be lost.
When CA OPS/MVS starts up, it loads all relational tables into memory and checks the integrity of data in the tables. If any data is damaged, CA OPS/MVS either repairs the damage or marks the affected table as inaccessible.
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