Multiversion views: Constructing views in a multiversion database

摘要

Commercial DBMS offer mechanisms for views and for versions. Research and development efforts in these directions are, however, characterized by concentration on either the one or the other mechanism, very seldom trying to take advantage of their complementary properties. This paper presents the multiversion view mechanism, which allows these orthogonal concepts to be managed together, taking advantage of their combined characteristics. Unlike previous efforts to combine views and versions, multiversion views create views over versions of data, thereby offering users coherent logical units of the versioned world. They allow a wide range of (virtual) data reorganization possibilities, which encompass, among others, operations found in temporal databases and OLAP. Multiversion views are illustrated and motivated by needs from a real life large case study of complex configuration management, described at the end of the paper.