Overview

The caGrid Federated Query Processor (FQP) Infrastructure provides a mechanism to perform basic distributed aggregations and joins of queries over multiple data services. As caGrid data services all use a uniform query language, CQL, as well as a uniform grid interface, the Federated Query Infrastructure can be used to express queries over any combination of caGrid data services. Federated queries are expressed with a query language, DCQL, which is an extension to CQL to express such concepts as joins against other data services, aggregations, and target data services.