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ILOG: Declarative Creation and Manipulation of Object Identifiers
, 1991
"... yosikawaQkyotosu.ac.jp Abstract: This paper introduces ILOG ( a declarative language in the style of (stratified) datalog ( which can be used for querying, schema translation, and schema augmentation in the context of objectbased data models. The semantics of ILOG is based on the use of Skolem fun ..."
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Cited by 106 (1 self)
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yosikawaQkyotosu.ac.jp Abstract: This paper introduces ILOG ( a declarative language in the style of (stratified) datalog ( which can be used for querying, schema translation, and schema augmentation in the context of objectbased data models. The semantics of ILOG is based on the use of Skolem functors, and is closely related to semantics for objectbased data manipulation languages which provide mechanisms for explicit creation of object identifiers (OIDs). A normal form is presented for ILOG ’ programs not involving recursion through OID creation, which identifies a precise correspondence between OIDs created in the target, and values and OIDs in the source. The expressive power of various sublanguages of ILOG ’ is shown to range from a natural generalization of the conjunctive queries to the objectbased context, to a language which can specify all computable database translat.ions (up to duplicate copies). The issue of testing vuliilityof ILOG programs translat.ing one semantic schema to another is studied: cases are presented for which severalvalidity issues (e.g., functional and/or subset relationships in the
The COCOON Object Model
, 1994
"... The COCOON model was intended to extend the concepts of relational database management systems (DBMSs) beyond nested relational to objectoriented ones. Key characteristics of COCOON and its database language COOL are: generic, setoriented query and update operators similar to relational algebra an ..."
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Cited by 63 (21 self)
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The COCOON model was intended to extend the concepts of relational database management systems (DBMSs) beyond nested relational to objectoriented ones. Key characteristics of COCOON and its database language COOL are: generic, setoriented query and update operators similar to relational algebra and SQL updates, respectively; objectpreserving semantics of query operators, which allows for the definition of updatable views; update operations that keep modelinherent integrity constraints consistent; a separation of the two aspects of programming language "classes": type vs. collection; predicative description of collections, similar to "defined concepts" in KLOnelike knowledge representation languages; automatic classification of objects and views (positioning in the class hierarchy). This report gives a comprehensive introduction to the COCOON model and its language COOL as well as a formal definition. Our formalization uses denotational semantics, a popular technique in programming...
On the expressive power of database queries with intermediate types
 Journal of Computer and System Sciences
, 1991
"... The setheight of a complex object type is defined to be its level of nesting of the set construct. In a query of the complex object calculus which maps a database D to an output type T,anintermediate type is a type which is used by some variable of the query, but which is not present in D or T.Fore ..."
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Cited by 47 (2 self)
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The setheight of a complex object type is defined to be its level of nesting of the set construct. In a query of the complex object calculus which maps a database D to an output type T,anintermediate type is a type which is used by some variable of the query, but which is not present in D or T.Foreachk, i ≥ 0 we define CALCk,i to be the family of calculus queries mapping from and to types with setheight ≤ k and using intermediate types with setheight ≤ i. In particular, CALC0,0 is the classical relational calculus, and CALC0,1 is equivalent to the family of secondorder (relational) queries. Several results concerning these families of languages are obtained. A primary focus is on the families CALC0,i, which map relations to relations. Upper and lower bounds in terms of hyperexponential time and space on the complexity of these families are provided. The CALC0,i hierarchy does not collapse with respect to expressive power. The union ∪0≤iCALC0,i is exactly the family of elementary queries, i.e., queries with hyperexponential complexity. The expressive power of queries from the complex object calculus interpreted using semantics based on the use of arbitrarily large finite or infinite set of invented values is studied. Under these semantics, the expressive power of the relational calculus is not increased, and the CALC0,i hierarchy collapses at CALC0,1. In general, queries with these semantics may not be computable. We also consider an alternative semantics which yields a family of queries equivalent to the computable queries. 1
Bibliography: Temporal Databases
 ACM SIGMOD Record
, 1986
"... 17. COSATI CODES j18. SUBJECT TERMS (Continue an revetse If necensaiy and Identify by block number' ..."
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Cited by 44 (4 self)
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17. COSATI CODES j18. SUBJECT TERMS (Continue an revetse If necensaiy and Identify by block number'
Hypothetical Datalog: Complexity and Expressibility
 Theoretical Computer Science
, 1988
"... We present an extension of Hornclause logic which can hypothetically add and delete tuples from a database. Such logics have been discussed in the literature, but their complexities and expressibilities have remained an open question. This paper examines two such logics in the functionfree, predic ..."
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Cited by 39 (14 self)
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We present an extension of Hornclause logic which can hypothetically add and delete tuples from a database. Such logics have been discussed in the literature, but their complexities and expressibilities have remained an open question. This paper examines two such logics in the functionfree, predicate case. It is shown, in particular, that augmenting Hornclause logic with hypothetical addition increases its datacomplexity from PTIME to PSPACE. When deletions are added as well, complexity increases again, to EXPTIME. We then augment the logic with negationasfailure and develop the notion of stratified hypothetical rulebases. It is shown that negation does not increase complexity. To establish expressibility, we view the logic as a query language for relational databases. It is shown that any typed generic query that is computable in PSPACE can be expressed as a stratified rulebase of hypothetical additions. Similarly, any typed generic query that is computable in EXPTIME can be exp...
RUL: A Declarative Update Language for RDF
 In ISWC
, 2005
"... Abstract. We propose a declarative update language for RDF graphs which is based on the paradigms of query and view languages RQL and RVL. Our language, called RUL, ensures that the execution of the update primitives on nodes and arcs neither violates the semantics of the RDF model nor the semantics ..."
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Cited by 25 (7 self)
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Abstract. We propose a declarative update language for RDF graphs which is based on the paradigms of query and view languages RQL and RVL. Our language, called RUL, ensures that the execution of the update primitives on nodes and arcs neither violates the semantics of the RDF model nor the semantics of the given RDFS schema. In addition, RUL supports finegrained updates at the class and property instance level, setoriented updates with a deterministic semantics and takes benefit of the full expressive power of RQL for restricting the range of variables to nodes and arcs of RDF graphs. 1
Domain Independence and the Relational Calculus
 Acta Informatica
, 1993
"... Several alternative semantics (or interpretations) of the relational (domain) calculus are studied here. It is shown that they all have the same expressive power, i.e., the selection of any of the semantics neither gains nor loses expressive power. Since the domain is potentially infinite, the answe ..."
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Cited by 24 (7 self)
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Several alternative semantics (or interpretations) of the relational (domain) calculus are studied here. It is shown that they all have the same expressive power, i.e., the selection of any of the semantics neither gains nor loses expressive power. Since the domain is potentially infinite, the answer to a relational calculus query is sometimes infinite (and hence not a relation). The following approaches which guarantee the finiteness of answers to queries are studied here: outputrestricted unlimited interpretation, domain independent queries, outputrestricted finite and countable invention, and limited interpretation. Of particular interest is the outputrestricted unlimited interpretation  although the output is restricted to the active domain of the input and query, the quantified variables range over the infinite underlying domain. While this is close to the intuitive interpretation given to calculus formulas, the naive approach to evaluating queries under this semantics calls ...
Fundamental properties of deterministic and nondeterministic extensions of Datalog
 Theoretical Computer Science
, 1991
"... Fundamental properties of deterministic and nondeterministic extensions of Datalog from [AV88] are studied. The extensions involve the use of negative literals both in bodies and heads of rules. Negative literals in heads are interpreted as deletions. A deterministic semantics is obtained by firi ..."
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Cited by 21 (2 self)
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Fundamental properties of deterministic and nondeterministic extensions of Datalog from [AV88] are studied. The extensions involve the use of negative literals both in bodies and heads of rules. Negative literals in heads are interpreted as deletions. A deterministic semantics is obtained by firing in parallel all applicable rules. The nondeterministic semantics results from firing (nondeterministically) one rule at a time. In the nondeterministic case, programs do not describe functions but relations between database states. In both cases, the result is an increase in expressive power over Datalog. The price for it is that programs do not always terminate. We study when a program (i) is such that on a given input, all its successful computations reach a unique fixpoint, (ii) yields at least one output on every input and (iii) has only loopfree computations. We also show how to simulate programs containing loops by loopfree programs. Work supported by the Projet de Recherc...
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 17 (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...
Deterministic Semantics of SetOriented Update Sequences
 In Proceedings, Ninth International Conference on Data Engineering
, 1993
"... An iterator is proposed that allows to apply sequences of update operations in a setoriented way with deterministic semantics. Because the mechanism is independent of a particular model, it can be used in the relational and in objectoriented ones. Thus, the deterministic semantics of embedded SQL ..."
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Cited by 13 (4 self)
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An iterator is proposed that allows to apply sequences of update operations in a setoriented way with deterministic semantics. Because the mechanism is independent of a particular model, it can be used in the relational and in objectoriented ones. Thus, the deterministic semantics of embedded SQL cursors, and of triggers that are applied after (setoriented) SQL updates can be checked. Furthermore, the iterator can be used to apply objectoriented methods, which are usually update sequences defined on a single object, also to sets in a deterministic way. It turns out that the criteria that guarantee determinism are also used in semantic or multilevel concurrency control. 1 Introduction The paper deals with the general problem of defining update languages that are comparable in expressive power to typical query languages. When designing such an update language, one should pursue the following objectives: ffl genericity: update operations should be applicable to all types of objects...