Recursively indefinite databases
نویسندگان
چکیده
منابع مشابه
Recursively Indeenite Databases 1
We deene recursively indeenite databases, a new type of logical database in which indeenite information arises from partial knowledge of the xpoint of a Datalog program. Although, in general, query answering is undecidable, we show that queries containing only basic predicates and monadic deened predicates are decidable. The main contribution of the paper is an analysis of the complexity of que...
متن کاملIndefinite and GCWA Inference in Indefinite Deductive Databases
This paper presents several basic results on compiling indefinite and GCWA(Generalized Closed World Assumption) inference in IDDB(Indefinite Dedutive Databases). We do not allow function symbols, but do allow non-Horn clauses. Further, although the GCWA is used to derive negative assumptions, we do also allow negative clauses to occur explicitly. We show a fundamental relationship between indef...
متن کاملThe View-Update Problem for Indefinite Databases
This paper introduces and studies a declarative framework for updating views over indefinite databases. An indefinite database is a database with null values that are represented, following the standard database approach, by a single null constant. The paper formalizes views over such databases as indefinite deductive databases, and defines for them several classes of database repairs that real...
متن کاملIndefinite Information with Certainty Factors for Object-Oriented Databases
This paper presents an approach to integrate the concepts of indefinite information with certainty factor in an object-oriented framework. In this work, the concept of traditional indefinite information is extended to include certainty factors so that indefiniteness can be measured. Indefinite information with certainty factors is classified into two categories: certainty factors of association...
متن کاملThe Complexity of Query Evaluation in Indefinite Temporal Constraint Databases
In previous work we have developed the scheme of indeenite L-constraint databases where L, the parameter, is a rst-order constraint language. This scheme extends the constraint database proposal of Kanellakis, Kuper and Revesz to include in-deenite (or uncertain) information in the style of Imielinski and Lipski. In this paper we study the complexity of query evaluation in an important instance...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Theoretical Computer Science
سال: 1993
ISSN: 0304-3975
DOI: 10.1016/0304-3975(93)90223-g