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24
Logic and databases: a deductive approach
 ACM Computing Surveys
, 1984
"... The purpose of this paper is to show that logic provides a convenient formalism for studying classical database problems. There are two main parts to the paper, devoted respectively to conventional databases and deductive databases. In the first part, we focus on query languages, integrity modeling ..."
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Cited by 143 (2 self)
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The purpose of this paper is to show that logic provides a convenient formalism for studying classical database problems. There are two main parts to the paper, devoted respectively to conventional databases and deductive databases. In the first part, we focus on query languages, integrity modeling and maintenance, query optimization, and data
Finding Regular Simple Paths In Graph Databases
, 1989
"... We consider the following problem: given a labelled directed graph G and a regular expression R, find all pairs of nodes connected by a simple path such that the concatenation of the labels along the path satisfies R. The problem is motivated by the observation that many recursive queries in relatio ..."
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Cited by 109 (5 self)
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We consider the following problem: given a labelled directed graph G and a regular expression R, find all pairs of nodes connected by a simple path such that the concatenation of the labels along the path satisfies R. The problem is motivated by the observation that many recursive queries in relational databases can be expressed in this form, and by the implementation of a query language, G+ , based on this observation. We show that the problem is in general intractable, but present an algorithm than runs in polynomial time in the size of the graph when the regular expression and the graph are free of conflicts. We also present a class of languages whose expressions can always be evaluated in time polynomial in the size of both the graph and the expression, and characterize syntactically the expressions for such languages. Key words. Labelled directed graphs, NPcompleteness, polynomialtime algorithms, regular expressions, simple paths AMS(MOS) subject classifications. 68P, 6...
Computable Queries for Relational Databases
, 1980
"... this paper is to settle the question of maximal expressiveness of query languages. This is done in two steps. First, the set of computable queries is defined. These correspond to partial recursive functions which satisfy a consistency criterion reflecting the fact that the computation is on a data b ..."
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Cited by 83 (0 self)
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this paper is to settle the question of maximal expressiveness of query languages. This is done in two steps. First, the set of computable queries is defined. These correspond to partial recursive functions which satisfy a consistency criterion reflecting the fact that the computation is on a data base rather than, say, on a natural number
Linear constraint query languages: Expressive power and complexity
 Logic and Computational Complexity
, 1994
"... Abstract. We giveanAC 0 upper bound on the complexity of rstoder queries over (in nite) databases de ned by restricted linear constraints. This result enables us to deduce the nonexpressibility ofvarious usual queries, such as the parity of the cardinality of a set or the connectivity of a graph i ..."
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Cited by 25 (12 self)
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Abstract. We giveanAC 0 upper bound on the complexity of rstoder queries over (in nite) databases de ned by restricted linear constraints. This result enables us to deduce the nonexpressibility ofvarious usual queries, such as the parity of the cardinality of a set or the connectivity of a graph in rstorder logic with linear constraints. 1
Structural Characterizations of SchemaMapping Languages
, 2009
"... Schema mappings are declarative specifications that describe the relationship between two database schemas. In recent years, there has been an extensive study of schema mappings and of their applications to several different data interoperability tasks, including applications to data exchange and d ..."
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Cited by 20 (3 self)
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Schema mappings are declarative specifications that describe the relationship between two database schemas. In recent years, there has been an extensive study of schema mappings and of their applications to several different data interoperability tasks, including applications to data exchange and data integration. Schema mappings are expressed in some logical formalism that is typically a fragment of firstorder logic or a fragment of secondorder logic. These fragments are chosen because they possess certain desirable structural properties, such as existence of universal solutions or closure under target homomorphisms. In this paper, we turn the tables and focus on the following question: can we characterize the various schemamapping languages in terms of structural properties possessed by the schema mappings specified in these languages? We obtain a number of characterizations of schema mappings specified by sourcetotarget (st) dependencies, including characterizations of schema mappings specified by LAV (localasview) st tgds, schema mappings specified by full st tgds, and schema mappings specified by arbitrary st tgds. These results shed light on schemamapping languages from a new perspective and, more importantly, demarcate the properties of schema mappings that can be used to reason about them in data interoperability applications.
Creating and Filtering Structural Data Visualizations using Hygraph Patterns
, 1994
"... Data visualization plays a fundamental role in helping users solve complex, informationintensive problems in scientific, engineering and business applications. This thesis introduces an original framework for the use of queries to create and filter structural data visualizations (a term we introduc ..."
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Cited by 15 (3 self)
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Data visualization plays a fundamental role in helping users solve complex, informationintensive problems in scientific, engineering and business applications. This thesis introduces an original framework for the use of queries to create and filter structural data visualizations (a term we introduce to refer to the diagrammatic display of the relationships of structured data). Hygraphs, a new visual formalism, provides a precise characterization of the diagrammatic visualizations considered. This simple formalism is a convenient abstraction for both graphbased and formbased (or tabular) presentations. We present theoretical and practical contributions that exploit the synergism between the established field of database query languages and the emerging area of visualization. On the database theory side, we...
The Expressive Power of Stratified Logic Programs with Value Invention
 IN ICDT'95 (FIFTH INTERNATIONAL CONFERENCE ON DATA BASE THEORY), PRAGUE, LECTURE NOTES IN COMPUTER SCIENCE 893
, 1996
"... The expressive power of the family wILOG (:) of relational query languages is investigated. The languages are rule based, withvalue invention and stratified negation. The semantics for value invention is based on Skolem functor terms. Westudy a hierarchy of languages based on thenumber of strata ..."
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Cited by 15 (1 self)
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The expressive power of the family wILOG (:) of relational query languages is investigated. The languages are rule based, withvalue invention and stratified negation. The semantics for value invention is based on Skolem functor terms. Westudy a hierarchy of languages based on thenumber of strata allowed in programs. We first show that, in presence of value invention, the class of stratified programs madeoftwo stratahas the whole expressive power of the family, thus expressing the computable queries. Wethen show that the language wILOG 6= of programs with non+ y and without negation expresses the monotone queries, and that the language wILOG 1 2 #: of semipositive programs expresses the semimonotone queries.
On the Completeness of ObjectCreating Database Transformation Languages
"... Objectoriented applications of database systems require database transformations involving nonstandard functionalities such as set manipulation and object creation, i.e., the introduction of new domain elements. To deal with these functionalities, Abiteboul and Kanellakis introduced the "determina ..."
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Cited by 14 (9 self)
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Objectoriented applications of database systems require database transformations involving nonstandard functionalities such as set manipulation and object creation, i.e., the introduction of new domain elements. To deal with these functionalities, Abiteboul and Kanellakis introduced the "determinate" transformations as a generalization of the standard domainpreserving transformations. The obvious extensions of complete standard database programming languages, however, are not complete for the determinate transformations. To remedy this mismatch, the "constructive" transformations are proposed. It is shown that the constructive transformations are precisely the transformations that can be expressed in said extensions of complete standard languages. Thereto, a close correspondence between object creation and the construction of hereditarily finite sets is established. A restricted version of the main completeness result for the case where only list manipulations are involved is also ...
Evaluating the Completeness of TSQL2
, 1995
"... This paper applies important existing completeness notions to TSQL2 in ..."
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Cited by 14 (8 self)
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This paper applies important existing completeness notions to TSQL2 in
An extension of the relational data model to incorporate ordered domains
 ACM Transactions on Database Systems
, 2001
"... We extend the relational data model to incorporate partial orderings into data domains, which we call the ordered relational model. Within the extended model, we define the Partially Ordered Relational Algebra (the PORA) by allowing the ordering predicate ⊑ to be used in formulae of the selection op ..."
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Cited by 11 (2 self)
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We extend the relational data model to incorporate partial orderings into data domains, which we call the ordered relational model. Within the extended model, we define the Partially Ordered Relational Algebra (the PORA) by allowing the ordering predicate ⊑ to be used in formulae of the selection operator (σ). The PORA expresses exactly the set of all possible relations which are invariant under orderpreserving automorphism of databases. This result characterises the expressiveness of the PORA and justifies the development of Ordered SQL (OSQL) as a query language for ordered databases. OSQL provides users with the capability of capturing the semantics of ordered data in many advanced applications, such as those having temporal or incomplete information. Ordered Functional Dependencies (OFDs) on ordered databases are studied, based on two possible extensions of domain orderings: (1) pointwiseordering and (2) lexicographical ordering. We present a sound and complete axiom system for OFDs in the first case and establish a set of sound and complete chase rules for OFDs in the second. Our results suggest that the implication problems for both cases of OFDs are decidable and that the enforcement of OFDs in ordered relations are practically feasible. In a wider perspective, the proposed model explores an important area of objectrelational databases, since ordered domains can be viewed as a general kind of data type. Categories and Subject Descriptors: H.2.1 [Database Management]: Logical Design—data