Here we report a performance evaluation using a synthetic workload based on the multi-version archive of WWW pages collected by the AT&T Internet Difference Engine (described above in Section 3.1). This archive reflected the actual evolution of the pages, although it did not contain copies of every version of every page: some pages were archived automatically once per day when changes were detected, while the majority were archived upon the explicit instruction of a user of the system.
Slightly over half of the pages had only one version archived; these reflected pages that were registered with the system but had either never changed or (more likely) were not archived automatically and had not been selected for subsequent archival by a user. We excluded these pages from the benchmark because no deltas were available. On the other hand, about 10% of the 380 pages had 10 or more versions archived, and several had 50 or more versions (the latter were all pages that were archived automatically).