Skippy: Enabling Long-Lived Snapshots of the Long-Lived Past

Decreasing disk costs have made it practical to retain long- lived snapshots, enabling new applications that analyze past states and infer about future states. Current approaches offer no satisfactory way to organize long-lived snapshots because they disrupt the database in either short or long run. Split snapshots are a recent approach that overcomes some of the limitations. An unsolved problem has been how to support efficient application code access to arbitrarily long-lived snapshots. We describe Skippy, a new approach that solves this problem. Performance evaluation of Skippy, based on theoretical analysis and experimental measurements, indicates that the new approach is effective and efficient.