1. A method of submitting a federated query to one or more data sources belonging to a federation, comprising: splitting a zone into a plurality of zone subsets, the zone including a plurality of data sources belonging to a federation, and the plurality of zone subsets having disjoint sets of data sources belonging to the federation; receiving a federated query from a client, the federated query including a plurality of source queries, and each source query of the plurality of source queries being specific to an autonomous data source belonging to the federation; determining the client's assigned zone subset of the plurality of zone subsets; and submitting the federated query to the client's assigned zone subset, wherein the plurality of source queries is submitted to one or more data sources in the client's assigned zone subset.