Metareasoning Agents for Query-Answering Systems

Barklund, Jonas; Costantini, Stefania; Dell'Acqua, Pierangelo; Lanzarone, Gaetano Aurelio

doi:10.1007/978-1-4615-6075-3_6

Cited by 4 publications

(3 citation statements)

References 8 publications

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“…The vertical arrows between S and Q, and S and Q , respectively, indicate that Q and Q are sets of queries and views defined on S and S , respectively. Unfortunately, it is not always possible to find a synchronization for all the queries and views upon a schema modification, especially when the schema evolution is capacity reducing (see Lakshmanan et al [1993] and Rundensteiner et al [1997]) or when the schema is considerably altered (see Barklund et al [1997] and Polese and Vacca [2009a]). In these cases, it is necessary to decide whether the query/view must be dropped or the schema evolution inhibited, in order to preserve the correct functioning of all the queries and views.…”

Section: The Qvs Processmentioning

confidence: 99%

Synchronization of Queries and Views Upon Schema Evolutions

Caruccio

Polese

Tortora

2016

ACM Trans. Database Syst.

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One of the problems arising upon the evolution of a database schema is that some queries and views defined on the previous schema version might no longer work properly. Thus, evolving a database schema entails the redefinition of queries and views to adapt them to the new schema. Although this problem has been mainly raised in the context of traditional information systems, solutions to it are also advocated in other database-related areas, such as Data Integration, Web Data Integration, and Data Warehouses. The problem is a critical one, since industrial organizations often need to adapt their databases and data warehouses to frequent changes in the real world. In this article, we provide a survey of existing approaches and tools to the problem of adapting queries and views upon a database schema evolution; we also propose a classification framework to enable a uniform comparison method among many heterogeneous approaches and tools.

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Section: The Qvs Processmentioning

confidence: 99%

Synchronization of Queries and Views Upon Schema Evolutions

Caruccio

Polese

Tortora

2016

ACM Trans. Database Syst.

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“…The idea of RCL came from the observation that Reflection principles can specify not only the shift between levels, but also many other meta-reasoning principles. For instance, reflection principles can define forms of analogical reasoning [21], and synchronous communication among logical agents [6,12].…”

Section: Meta-reasoning and Reflection In Artificial Intelligencementioning

confidence: 99%

Elio Lanzarone: a life for science

Costantini

Gobbo

2013

Journal of Logic and Computation

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We are sincerely grateful to have been invited by the Guest Editor of this special issue, Prof. Francesca Lisi, to write an article in honor of our mentor Gaetano Aurelio Lanzarone (for students, colleagues and friends simply 'Elio'). We were the first (Stefania) and last (Federico) of Elio's students, and we both entertained a particularly deep relation with him. What we want to do here is to provide a memoir of his life and career, while his smile, laughter and humor cannot be described in words, but only in the language of our hearts and memories. We believe that Elio's attitude towards life is well described by the words that Dante Alighieri in his 'Divina Commedia' (Divine Comedy, Inferno [Hell], Chant XXVI) attributes to Ulysses: 'Considerate la vostra semenza: fatti non foste a viver come bruti, ma per seguir virtute e canoscenza' ('Call to mind from whence ye sprang: Ye were not form'd to live the life of brutes, But virtue to pursue and knowledge high').

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“…A formalization of analogical reasoning in this reflective logic was elaborated in [25]. Reflection was used to represent communication among different theories/agents in [10,20]. The very idea that a common view underlying such diverse contexts could be systematized in the unifying framework of reflection principles was first advanced in [21].…”

Section: Related Work and Concluding Remarksmentioning

confidence: 99%

Reflection principles in computational logic

Dell'Acqua

2000

Journal of Logic and Computation

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We introduce the concept of reflection principle as a knowledge representation paradigm in a computational logic setting. Reflection principles are expressed as certain kinds of logic schemata intended to capture the basic properties of the domain knowledge to be modelled. Reflection is then used to instantiate these schemata to answer specific queries about the domain. This differs from other approaches to reflection mainly in the following three ways. First, it uses logical instead of procedural reflection. Second, it aims at a cognitively adequate declarative representation of various forms of knowledge and reasoning, as opposed to reflection as a means for controlling computation or deduction. Third, it facilitates the building of a complex theory by allowing a simpler theory to be enhanced by a compact metatheory, contrary to the construction of metatheories that are only conservative extensions of the basic theory. A computational logic system for embedding reflection principles, called RCL (for Reflective Computational Logic), is presented in full detail. The system is an extension of Horn clause resolution-based logic, and is devised in a way that makes important features of reflection parametric as much as possible, so that they can be tailored according to specific needs of different application domains. Declarative and procedural semantics of the logic are described and correctness and completeness of reflection as logical inference are proved. Examples of reflection principles for three different application areas are shown. Relationship with a variety of distinct sources within the literature on relevant topics is discussed.

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Metareasoning Agents for Query-Answering Systems

Cited by 4 publications

References 8 publications

Synchronization of Queries and Views Upon Schema Evolutions

Synchronization of Queries and Views Upon Schema Evolutions

Elio Lanzarone: a life for science

Reflection principles in computational logic

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