Example 1: 4 CA groups

CA spill file example 1.

• 10 input logs
• 4 CA groups
• 3 parallel sort address spaces

Assume the log distribution is common to all groups. Each group processes logs 1 through 10. When log 1 is opened, all 4 CA groups must be started. Groups 1, 2, and 3 are started as address spaces and receive the log input directly using cross-memory data transfer. Because group 4 cannot use cross-memory, it will be directed to a spill file.

The DBRC VOLNUM parameter also affects the scheduling of address spaces and use of spill files. When a CA group requires more log files than the VOLNUM limit, DBRC creates multiple CA utility processing steps. These steps cannot be run in parallel because, after the first step, the input to each step is the output of the preceding step.