8. The system of claim 1 , further comprising a data structure that caches a uniform resource locator for a document predefined to be relevant to at least a portion of the query.
8. The system of claim 1 , further comprising a data structure that caches a uniform resource locator for a document predefined to be relevant to at least a portion of the query. 9. The system of claim 8 , wherein the server is further configured to determine the uniform resource locator for the document predefined to be relevant based on the at least a portion of the query cached in the data structure.