Query Containment for Databases with Uncertainty and Lineage.
Foto Afrati, Angelos Vasilakopoulos · 2010
Abstract. We define and investigate the computational complexity of the query containment problem for data that support both uncertainty and lineage. Query containment depends on the definition of database containment which, for traditional databases, is defined as a simple set containment for each relation. As this is not the case in the presence of uncertainty and lineage, we revisit the notion of database containment and define various kinds of it that may be natural in different practical situations. We investigate conjunctive query containment for the various kinds of query containment that we introduce.