𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Reflective Programming in the Relational Algebra

✍ Scribed by Jan Van den Bussche; Dirk van Gucht; Gottfried Vossen

Publisher
Elsevier Science
Year
1996
Tongue
English
Weight
485 KB
Volume
52
Category
Article
ISSN
0022-0000

No coin nor oath required. For personal study only.

✦ Synopsis

This paper introduces a reflective extension of the relational algebra. Reflection is achieved by storing and manipulating relational algebra programs as relations and by adding a LISP-like evaluation operation to the algebra. We first show that this extension, which we call the reflective algebra, can serve as a unifying formalization of various forms of procedural data management which have been considered in database systems research. We then study the expressive power and complexity of the reflective algebra. In particular, we establish a close correspondence between reflection and bounded looping, and between tailrecursive reflection and unbounded looping. These correspondences yield new logical characterizations of PTIME and PSPACE.

πŸ“œ SIMILAR VOLUMES

Polymorphic Type Inference for the Relat
Polymorphic Type Inference for the Relational Algebra
✍ Jan Van den Bussche; Emmanuel Waller πŸ“‚ Article πŸ“… 2002 πŸ› Elsevier Science 🌐 English βš– 179 KB

We give a polymorphic account of the relational algebra. We introduce a formalism of ''type formulas'' specifically tuned for relational algebra expressions, and present an algorithm that computes the ''principal'' type for a given expression. The principal type of an expression is a formula that sp

The Relation Reflection Scheme
The Relation Reflection Scheme
✍ Peter Aczel πŸ“‚ Article πŸ“… 2008 πŸ› John Wiley and Sons 🌐 English βš– 115 KB

## Abstract We introduce a new axiom scheme for constructive set theory, the Relation Reflection Scheme (RRS). Each instance of this scheme is a theorem of the classical set theory ZF. In the constructive set theory CZF^–^, when the axiom scheme is combined with the axiom of Dependent Choices (DC),

The reflection effect in time-related de
The reflection effect in time-related decisions
✍ Nobuhide Zushi; Eleonora Curlo; Gloria P. Thomas πŸ“‚ Article πŸ“… 2009 πŸ› John Wiley and Sons 🌐 English βš– 115 KB

## Abstract Despite the intuitive appeal of conceptualizing time as a resource, like money, to which prospect theory should apply, the application of prospect theory to time‐related decisions has met with mixed results. Existing literature has failed repeatedly to find evidence of loss aversion and

Braid Relations in the Yokonuma–Hecke Al
Braid Relations in the Yokonuma–Hecke Algebra
✍ J. Juyumaya; S.Senthamarai Kannan πŸ“‚ Article πŸ“… 2001 πŸ› Elsevier Science 🌐 English βš– 191 KB

In this note, we prove a theorem on a new presentation for the algebra of the endomorphisms of the permutation representation (Yokonuma-Hecke algebra) of a simple Chevalley group with respect to a maximal unipotent subgroup. This presentation is given using certain nonstandard generators.