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ON TEMPORAL DEDUCTIVE DATABASES
Author(s) -
Orgun Mehmet A.
Publication year - 1996
Publication title -
computational intelligence
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.353
H-Index - 52
eISSN - 1467-8640
pISSN - 0824-7935
DOI - 10.1111/j.1467-8640.1996.tb00261.x
Subject(s) - datalog , deductive database , computer science , temporal database , programming language , temporal logic , extension (predicate logic) , relational algebra , set (abstract data type) , relational database , linear temporal logic , database , theoretical computer science
This article introduces a temporal deductive database system featuring a logic programming language and an algebraic front‐end. The language, called Temporal DATALOG, is an extension of DATALOG based on a linear‐time temporal logic in which the flow of time is modeled by the set of natural numbers. Programs of Temporal DATALOG are considered as temporal deductive databases, specifying temporal relationships among data and providing base relations to the algebraic front‐end. The minimum model of a given Temporal DATALOG program is regarded as the temporal database the program models intensionally. The algebraic front‐end, called TRA, is a point‐wise extension of the relational algebra upon the set of natural numbers. When needed during the evaluation of TRA expressions, slices of temporal relations over intervals can be retrieved from a given temporal deductive database by bottom‐up evaluation strategies. A modular extension of Temporal DATALOG is also proposed, through which temporal relations created during the evaluation of TRA expressions may be fed back to the deductive part for further manipulation. Modules therefore enable the algebra to have full access to the deductive capabilities of Temporal DATALOG and to extend it with nonstandard algebraic operators. This article also shows that the temporal operators of TRA can be simulated in Temporal DATALOG by program clauses.