3. The method of claim 1 , wherein selecting the partition of the user-term index that is associated with the user identifier comprises: performing a hash function to associate the user identifier to a particular partition of the user-term index; and selecting the particular partition of the user-term index.
3. The method of claim 1 , wherein selecting the partition of the user-term index that is associated with the user identifier comprises: performing a hash function to associate the user identifier to a particular partition of the user-term index; and selecting the particular partition of the user-term index. 6. The method of claim 3 , wherein the hash function takes a modulo of the user identifier by the number of partitions.