A system, computer usable medium and computer-based method for altering a sequence number assignment pattern while preserving integrity and high concurrency in an environment having a plurality of applications on at least one computer system sharing a direct access storage device (DASD). The method generates and assigns sequence numbers for a shared sequence object located on the shared DASD to a plurality of applications executing concurrently and using the shared sequence object. When an application starts altering the shared sequence object attribute(s) during concurrent assignment of sequence numbers by other applications, it notifies all computer systems using the shared sequence object to locally refresh the sequence object attribute descriptor and discard unused reserved sequence numbers, and then updates the altered shared sequence object attribute and last assigned sequence number on the shared DASD.