DFSSBEV0

DFSSBEV0 is a CSECT within load module DFSSBIL0. It is the driver module which evaluates the sequential buffering process. It individually evaluates each pair of DSG/DCBs which are or may be buffered by SB (sequential buffering).

DFSSBEV0 is called during:

·   logical data set open time

·   early evaluation (shortly after open)

·   periodic evaluation

·   final call/termination

·   statistical accumulation

Based upon the evaluation, DFSSBEV0 may change the status of the SDSG, dynamically activate or deactivate SB, and acquire buffers.

DFSSBEV0 calls DFSSBEV1 to perform the majority of the evaluation work, and calls DFSSBEV2 to acquire buffers.

Reference Sources

More information is available in the IMS DBSOURCE Library Data Set. See your IMS systems programmer.