Patent ID: 7203670

Claim:
A method for enhancing VSAM files online availability, comprising: switching online traffic from a first group of files to a second group of files, wherein the first group of files is identified by a first name and the second group of files is identified by a second name, and the first group of files identified by the first name contain old data and the second group of files identified by the second name contain new data; obtaining exclusive control of the first group of files; renaming the first group of files from the first name to a third name, during which online traffic accesses the second group of files; switching online traffic from the second group of files to the first group of files currently identified by the third name; obtaining exclusive control of the second group of files; renaming the second group of files from the second name to the first name, during which online traffic accesses the first group of files; switching online traffic from the first group of files currently identified by the third name to the second group of files currently identified by the first name; obtaining exclusive control of the first group of files currently identified by the third name; and renaming the first group of files currently identified by the third name to the second name, during which online traffic accesses the second group of files; whereby at least one of the first and second groups of files is available for online traffic during each of the renaming steps.