Modeling Functional Data Sources as Relations

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.

• Type: Conference
• Year: 2004
• Where: ER
• Authors: Simone Santini, Amarnath Gupta
• Keywords: Data Source, ER 2004, Functional Access, Optimal Plan