3. The method of claim 1 , further comprising: receiving an initial query; and generating, based on the initial query, a set of one or more subsequent queries, wherein the set of one or more subsequent queries includes the particular query.
3. The method of claim 1 , further comprising: receiving an initial query; and generating, based on the initial query, a set of one or more subsequent queries, wherein the set of one or more subsequent queries includes the particular query. 4. The method of claim 3 , further comprising, if the particular query is associated with the lowest cost relative to other queries in the set of one or more subsequent queries, then executing the particular query.