6. The method of claim 1 wherein the generating of the time-independent query model includes identifying queries that are causally related to the query and the time-independent query model predicts frequency of the query based on the frequency of the causally related queries.
6. The method of claim 1 wherein the generating of the time-independent query model includes identifying queries that are causally related to the query and the time-independent query model predicts frequency of the query based on the frequency of the causally related queries. 7. The method of claim 6 wherein a first query is causally related to a second query based on a causal relationship between an event of the first query and events of the second query.