A language for the integration of web sources

This is an electronic version of the paper presented at the IADIS International Conference WWW / INTERNET 2006, held in Murcia on 2006This paper presents a language for the creation of data sources in mediation systems through navigation in web sites. The general idea of the language is to “thread together,” so to speak, existing systems that parse and analyze single web pages into a navigation procedure spanning several pages of a web site, pages from different web sites, or web pages and other data repositories

Modeling functional data sources as relations

Abstract. In this paper we present a model of functional access to data that, we argue, is suitable for modeling a class of data repositories characterized by functional access, such as web sites. We discuss the problem of modeling such data sources as a set of relations, of determining whether a given query expressed on these relations can be translated into a combination of functions defined by the data sources, and of finding an optimal plan to do so. We show that, if the data source is modeled as a single relation, an optimal plan can be found in a time linear in the number of functions in the source but, if the source is modeled as a number of relations that can be joined, finding the optimal plan is NP-hard.