On subsequent reads of data maps, PowerExchange retrieves the data maps from

job-level

memory, which eliminates the overhead of enqueues, opens, points, reads, and closes of the data maps KSDS file.

When a data map changes or is deleted, PowerExchange deletes the copy of that data map in the cache. For changed data maps, PowerExchange does not add the data map to the cache again until the data map is actually used.

Single-job mode is more efficient than multiple-jobs mode because in single-job mode, the PowerExchange Listener job is the only job that updates the data maps file and the data maps cache does not become stale. Consequently, PowerExchange never needs to completely clear the cache like it does in multiple-jobs mode.

To configure PowerExchange to run data maps caching in single-job mode, define the following DBMOVER configuration statement:

DMXCACHE_MULTIPLEJOBS=N

For information about the DMXCACHE_MULTIPLEJOBS statement, see DMXCACHE_MULTIPLEJOBS Statement.