Relational met a-answers
نویسنده
چکیده
A meta-answer is a set of statements that assert various properties of an answer to a database uery. These statements may qualify the validity or the completeness o 1 the answer, or they may characterize the answer abstractly. Meta-answers add meaning and insight to standard database answers. We describe an extension to the relational database model for representing properties of the stored data, and for computing meta-answers from these representations.
منابع مشابه
Plain Answers to Several Questions about Association/Independence Structure in Complete/Incomplete Contingency Tables
In this paper, we develop some results based on Relational model (Klimova, et al. 2012) which permits a decomposition of logarithm of expected cell frequencies under a log-linear type model. These results imply plain answers to several questions in the context of analyzing of contingency tables. Moreover, determination of design matrix and hypothesis-induced matrix of the model will be discusse...
متن کاملAn Extended Relational Algebra on Abstract Objects for Summarizing Answers to Queries
Answers to queries in terms of abstract objects are defined in the logical framework of first order predicate calculus. A partial algebraic characterisation of the supremum and of the infimum of abstract answers is given in an extended Relational Algebra of the Cylindric Algebra kind. Then, the form of queries is restricted in order to be able to compute answers without the cylindrification ope...
متن کاملData Exchange: Algorithm for Computing Maybe Answers for Relational Algebra Queries
The concept of certain answers is usually used in the definition of the semantics of answering queries in data exchange. But as certain answers are defined as a relation without null values, the approaches for answering queries over databases do not always lead to semantically correct answer. In order to obtain all possible semantically correct answers, maybe answers have been considered along ...
متن کاملA Study of Disjunctive Information in Fuzzy Relational Databases
This paper proposes a logical reconstruction of the classical fuzzy relational database model to accommodate fuzzy disjunctive information. In query processing, we use two supplementary measurements, matching information and extra information, to model the concepts of imprecision and uncertainty, respectively. We also use these two supplementary measurements to determine the quality of answers ...
متن کاملThe Exclusive-or Disjunctive Information in Relational Databases
In this paper, we propose an extended relational model to accommodate exclusive-or disjunctive information. The proposed model is defined by first-order logic. The answers to a query contain both sure answers and maybe answers. To guarantee that the manipulation power of the proposed model is as good as that of the classical relational model, we prove that the classical properties of the databa...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2005