Title :
Valid-Time Indeterminacy in Temporal Relational Databases: Semantics and Representations
Author :
Anselma, Luca ; Terenziani, Paolo ; Snodgrass, Richard T.
Author_Institution :
Dipt. di Inf., Univ. di Torino, Turin, Italy
Abstract :
Valid-time indeterminacy is "don\´t know when" indeterminacy, coping with cases in which one does not exactly know when a fact holds in the modeled reality. In this paper, we first propose a reference representation (data model and algebra) in which all possible temporal scenarios induced by valid-time indeterminacy can be extensionally modeled. We then specify a family of 16 more compact representational data models. We demonstrate their correctness with respect to the reference representation and analyze several properties, including their data expressiveness. Then, we compare these compact models along several relevant dimensions. Finally, we also extend the reference representation and a representative of compact representations to cope with probabilities.
Keywords :
knowledge representation; relational databases; temporal databases; algebra; artificial intelligence; data expressiveness; data model; knowledge representation formalisms; reference representation; temporal relational databases; valid-time indeterminacy; Artificial intelligence; Data mining; Data models; Database systems; Knowledge representation; Relational databases; Semantics; Temporal databases; artificial intelligence; database design; knowledge representation formalisms and methods; modeling and management;
Journal_Title :
Knowledge and Data Engineering, IEEE Transactions on
DOI :
10.1109/TKDE.2012.199