Cost Models DO Matter: Providing Cost Information for Diverse Data Sources in a Federated System

An important issue for federated systems of diverse data sources is optimizing cross-source queries, without building knowledge of individual sources into the optimizer. This paper describes a framework through which a federated system can obtain the necessary cost and cardinality information for optimization. Our framework makes it easy to provide cost information for diverse data sources, requires few changes to a conventional optimizer and is easily extensible to a broad range of sources. We believe our framework for costing is the first to allow accurate cost estimates for diverse sources within the context of a traditional cost-based optimizer.

• Type: Conference
• Year: 1999
• Where: VLDB
• Authors: Mary Tork Roth, Fatma Ozcan, Laura M. Haas
• Keywords: Database, Diverse Data Sources, Diverse Sources, Individual Sources, VLDB 1999