Author name cluster

Fernando Sáenz-Pérez

Possible papers associated with this exact author name in Arrow. This page groups case-insensitive exact name matches and is not a full identity disambiguation profile.

3 papers

2 author rows

I&C Journal 2020 Journal Article

HR-SQL: Extending SQL with hypothetical reasoning and improved recursion for current database systems

Susana Nieva
Fernando Sáenz-Pérez
Jaime Sánchez-Hernández

In this work we present a formalization, backed with a contrasted implementation, of a relational database language (called HR-SQL) that extends SQL in two aspects. On the one hand, including non-linear and mutual recursion. On the other hand, including hypothetical relations and queries. Regarding expressiveness, HR-SQL allows a novel form of hypothetical reasoning, completely integrated with recursive definitions. In addition, aggregate functions are added. Regarding formalization, the extended language is founded on a stratified fixpoint semantics based on logic programming techniques. We include results of the existence of such fixpoints. An algorithm that transforms a database containing hypothetical definitions into an equivalent one without hypothesis and its correctness proof are presented. Regarding the implementation, we introduce here a system that incorporates the aforementioned benefits and enhances former implementations in several areas. The current HR-SQL system is targeted to several state-of-the-art relational database systems, and could be used with any SQL-based system with minor modifications in the implementation.

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LOPSTR Conference 2016 Conference Paper

Intuitionistic Logic Programming for SQL

Fernando Sáenz-Pérez

Abstract Intuitionistic logic programming provides the notion of embedded implication in rule bodies, which can be used to reason about a current database modified by the antecedent. This can be applied to a system that translates SQL to Datalog to solve SQL WITH queries, for which relations are locally defined and can therefore be understood as locally added to the current database. In addition, assumptions in SQL queries as either adding or removing data can be modelled in this way as well, which is an interesting feature for decision-support scenarios. This work suggests a way to apply intuitionistic logic programming to SQL, and provides a pointer to a working system implementing this idea.

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LOPSTR Conference 2011 Conference Paper

A Declarative Embedding of XQuery in a Functional-Logic Language

Jesús Manuel Almendros-Jiménez
Rafael Caballero 0001
Yolanda García-Ruiz
Fernando Sáenz-Pérez

Abstract This paper addresses the problem of integrating a fragment of XQuery, a language for querying XML documents, into the functional-logic language \(\mathcal{TOY}\). The queries are evaluated by an interpreter, and the declarative nature of the proposal allows us to prove correctness and completeness with respect to the semantics of the subset of XQuery considered. The different fragments of XML that can be produced by XQuery expressions are obtained using the non-deterministic features of functional-logic languages. As an application of this proposal we show how the typical generate and test techniques of logic languages can be used for generating test-cases for XQuery expressions.

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