Normal backout processing includes:

• BT command processing;

• backing out an update command that received a nonzero response code; and

• internal transaction backout due to, for example, a timeout.

Cluster nuclei perform normal Adabas backout processing. Each nucleus reads the protection data needed to back out updates from its own Work data set/file. It does not need to read protection data from the other Work data sets/files in the cluster.