Patent ID: 7158999

Claim:
A computer-implemented method of reorganizing an ICF catalog comprising a key sequential data set (KSDS) BCS in a VSAM system while the catalog is open, the BCS comprising a data component and an index component, the reorganization method comprising the steps of: (a) opening the catalog with exclusive control; (b) creating a backup of the index component; (c) using a number of sequence set records of the index component, constructing a logical CI correlation table, the table indicating, for each data CI in the data set, a physical location of the CI in the data component and a logical location of the CI in key sequence order; (d) using the logical CI correlation table, reading data CIs from the data component out to an internal backup data set in potential logical key sequence order so as to form an ordered backup of the data without sorting; (e) clearing all data CIs in the data component and clearing the index component; (f) updating BCS VSAM control blocks so as to reflect an empty BCS; (g) reloading the data set from the ordered backup, sorting records if necessary, and using standard VSAM I/O to reload the data records and reconstruct the index; and (h) closing the catalog to update VVRs in a VVDS and re-sync the catalog with CAS.