DMCA
Intensional answers to database queries (1994)
| Venue: | IEEE Transactions on Knowledge and Data Engineering |
| Citations: | 43 - 8 self |
BibTeX
@ARTICLE{Motro94intensionalanswers,
author = {Amihai Motro},
title = {Intensional answers to database queries},
journal = {IEEE Transactions on Knowledge and Data Engineering},
year = {1994},
volume = {6},
pages = {444--454}
}
Share
 |
 |
 |
 |
||
OpenURL
Abstract
Abstract-In addition to data, database systems store various on keys, integrity constraints, class hierarchies), are often kinds of information about their data. Examples are class hierarchies, to define the various data classes and their relationships; integrity constraints, to state required relationships among the data; and inference rules, to define new classes in terms of known classes. This information is often referred to as intensional assumed as well, but little else is assumed. Notable examples of this approach are the various attempts to provide user interfaces to relational databases that achieve logical data independence; i.e., interpret queries that specify information (the data are referred to as extensional information). only a list of attributes and a condition, without naming the Recently, there have been several independent research works that suggested ways by which intensional information may be used to improve the conventional (extensional) database answers. Although each of these efforts developed its own specific methods, specific relations to which the attributes belong and how the relations should be joined (e.g., [12], [24]). Another example is interfaces that avoid returning empty answers they all share a common belief: Database answers would be by automatically broadening all queries whose answers are improved if accompanied by intensional statements that describe them more abstractly. In this paper, we study and compare the various approaches to intensional answers by using various classifications; we examine their relative merits with regard to key aspects; we discuss remaining issues; and we offer new research empty [7], [ 161. A system based in part on these ideas is FLEX [ 151, a formal language interface to relational databases designed to service satisfactorily users with different levels of expertise. Using only the definition of the database and directions. various data indices, FLEX interprets each and every input Index Terms- Database, database extension, database intension, query, cooperative answer, extensional answer, intensional that is presented to it, regardless of its formal correctness. FLEX is also cooperative: It never delivers empty answers answer without explanation or assistance. Recently, there have been several independent efforts aimed
Keyphrases
intensional answer integrity constraint database answer class hierarchy empty answer new class database intension formal language interface various data class logical data independence abstract-in addition cooperative answer extensional information input index term database intensional information database system notable example inference rule user interface key aspect relational database specific method various approach various classification new research specific relation various attempt common belief intensional statement several independent effort interpret query relative merit database extension different level extensional answer various data index formal correctness several independent research
