14. The method of claim 1 , wherein: the set of index portions includes a first index portion and a second index portion; the retrieving candidate value combinations includes: retrieving, from the first index portion, a first batch of value combinations, wherein the first batch includes a plurality of consecutive value combinations from the first index portion; identifying a first set of one or more candidate value combinations from the first batch of value combinations; retrieving, from the second index portion, a second batch of value combinations, wherein the second batch includes a plurality of consecutive value combinations from the second index portion; and identifying a second set of one or more candidate value combinations from the second batch of value combinations; and the comparing candidate value combinations includes comparing one or more candidate value combinations from the first set of candidate value combinations with one or more candidate value combinations from the second set of candidate value combinations in accordance with the query.
16. The method of claim 14 , wherein the first set of one or more candidate value combinations includes a plurality of candidate value combinations.