A Framework for Access Methods for Versioned Data Betty Salzberg, Linan Jiang, David B. Lomet, Manuel Barrena García, Jing Shan, and Evangelos Kanoulas   View Paper (PDF)   Return to Session 13: Indexing Techniques Abstract This paper presents a framework for understanding and constructing access methosds for versioned data. Records are associated with version ranges in a version tree. A minimal representation for the end set of a version range is given. We show how, within a page, a compact representation of a record can be made using start version of the version range only. Current-version splits, version-and-key splits and consolidations are explained. These operations preserve an invariant which allows visiting only one page at each level of the access method when doing exact-match search (no backtracking). Splits and consolidations also enable efficient stabbing queries by clustering data alive ata given version into a small number of data pages. Last, we survey the methods in the literature to show in what ways they conform or do not conform to our framework. These methods include temporal access methods, branched versioning access methods and spatio-splitting access methods. Our contribution is not to create a new access method but to bring to light fundamental properties of version-splitting access methods and to provide a blueprint for future versioned access methods. In addition, we have not made the unrealistic assumption that transactions creating a new version make only one update, and have shown how to treat multiple updates. ©2005 Association for Computing Machinery