Temporal Connectives versus Explicit Timestamps to Query Temporal Databases

Abiteboul, Serge; Herr, Laurent; Bussche, Jan Van den

doi:10.1006/jcss.1998.1598

Cited by 20 publications

(25 citation statements)

References 11 publications

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“…which is shown to be not expressible in first-order ETL in [1] and therefore is not expressible in its monodic fragment EMTL.…”

Section: Lemma 42 Unary Predicatesmentioning

confidence: 90%

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Monodic temporal logic with quantified propositional variables

Hussak

2011

Journal of Logic and Computation

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We extend the monodic fragment of first-order linear temporal logic to include right-linear grammar operators and quantification of propositional variables. Unlike propositional temporal logic, the use of grammar operators in first-order temporal logic is not equivalent to general propositional quantification, as the latter admit satisfiable formulae without countable models. We consider the decision problem for fragments where propositional quantification occurs outside of quantification of individual variables and temporal (grammar) operators. We show that if externally quantified propositions inside temporal operators occur within positive occurrences of universal quantifiers for individual variables then validity for all propositional prefix classes is recursively enumerable, and decidable in the two-variable case. Without this condition we show that, even with very severe restrictions on the first-order part of the logic, no non-trivial prefix class is recursively enumerable.

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“…which is shown to be not expressible in first-order ETL in [1] and therefore is not expressible in its monodic fragment EMTL.…”

Section: Lemma 42 Unary Predicatesmentioning

confidence: 90%

“…. some of which are designated as quantifiable, predicate symbols p 0 , p 1 where P i is quantifiable, p is an n-ary predicate symbol and any of the t i 's in p(t 1 , . .…”

Section: Languages and Modelsmentioning

confidence: 99%

Monodic temporal logic with quantified propositional variables

Hussak

2011

Journal of Logic and Computation

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“…However in their approach multiple granularities are handled within the object language explicitly. Abiteboul, Herr and Van den Bussche [1] study temporal query languages extended from first-order logic which resemble imperative programming languages. Bidoit and Objois [6] propose a family of slicing query languages, called SQTL languages.…”

Section: Related Workmentioning

confidence: 99%

Querying Historical Data Over Multiple Time-Lines

Orgun

2008

Math.comput.sci.

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In a temporal database, time-varying relations may be defined over multiple time-lines with varying rates of sampling and/or progress, for instance, multiple time series. There is a need to represent such data in a temporal model and provide query languages. In this paper, we propose a clocked temporal relational algebra, called , which supports temporal relations based on multiple time-lines. In the underlying model, temporal relations (historical data) are defined over clocks which are subsequences of an assumed global time-line. The algebra is uniform, it is a consistent extension of the relational algebra, and it includes a number of temporal operators to combine data based on different time-lines, as well as extensions of the operators of the relational algebra. The semantics of an operation of depends on the clocks of the relations involved in the operation as well as the relations. We outline a formal interpretation of expressions of , which also represent clocked relations, and sketch a naïve expression evaluation method.

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“…A finite set of such relations may be referred to as the timestamp representation of a temporal database [1].…”

Section: Temporal Data Models and Time Domainsmentioning

confidence: 99%

“…r1: A TS a [1,10] a [11,20] a [21,30] r2: A TS a [5,15] The results, R 1 through R 4 , of four possible definitions of the difference operator are given next, and are discussed in turn. The first result contains the times associated with value a in r 1 that are not associated with value a in r 2 .…”

Section: Introductionmentioning

confidence: 98%

Point-versus interval-based temporal data models

Böhlen

Busatto

Jensen

Proceedings 14th International Conference on Data Engineering

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The association of timestamps with various data items such as tuples or attribute values is fundamental to the management of time-varying information. Using intervals in timestamps, as do most data models, leaves a data model with a variety of choices for giving a meaning to timestamps. Specifically, some such data models claim to be point-based while other data models claim to be interval-based. The meaning chosen for timestamps is important-it has a pervasive effect on most aspects of a data model, including database design, a variety of query language properties, and query processing techniques, e.g., the availability of query optimization opportunities. This paper precisely defines the notions of point-based and interval-based temporal data models, thus providing a new, formal basis for characterizing temporal data models and obtaining new insights into the properties of their query languages. Queries in point-based models treat snapshot equivalent argument relations identically. This renders point-based models insensitive to coalescing. In contrast, queries in interval-based models give significance to the actual intervals used in the timestamps, thus generally treating non-identical, but possibly snapshot equivalent, relations differently. The paper identifies the notion of timefragment preservation as the essential defining property of an interval-based data model.

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Temporal Connectives versus Explicit Timestamps to Query Temporal Databases

Cited by 20 publications

References 11 publications

Monodic temporal logic with quantified propositional variables

Monodic temporal logic with quantified propositional variables

Querying Historical Data Over Multiple Time-Lines

Point-versus interval-based temporal data models

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