Exit XFCBOVER, file control backout override exit

Exit XFCBOVER is part of the support CICS® file control provides for batch windows in a VSAM RLS environment.

VSAM RLS locks individual records within a data set, and these locks are converted to retained locks for those UOWs that are not completed because of backout or indoubt failures, thus preserving data integrity. To avoid corruption of a data set by a non-RLS batch job, which is not aware of the retained record locks, a data set cannot normally be opened for update in non-RLS mode if it has any locked records.