Building the Architecture of A Statistics-Based Query Optimization Solution for Heterogeneous Mediators

Access to different and remote sources with heterogeneous formats is one of the most important challenges in Enterprise Information Integration. Even though there exists an increasing number of solutions which obtain information from structured and semistructured sources such as web sites, lack of Quality of Service in HTTP connections makes it very difficult to measure the mediated query performance. Different solutions based on relational and hierarchical optimization techniques have been proposed to improve query’s results, mainly in terms of time and space. This article proposes the utilization of some of these techniques in an integrated way, adding some concepts which help improve their functioning, all by using a specialized cost repository; some of them are the differentiation between positive and negative query capabilities or the use of search method’s utilization ranking in the cost repository. Besides, the article defines and explains how physical layer optimization by means of a configurable pool of browsers can help improve query’s result time in a non-despicable way.