what's the effect of permutations hash object?

[vega110]

At first, I only put RandomBinaryProjections hash in my codes, and it did not yield good results ,but I can repeat run my query function, not include index vector function, eg engine.store_vector(vector, data);

when I add HashPermutations object in my code. such as
permutations = HashPermutations('p')
rbp_conf = {'num_permutation':50, 'beam_size':10, 'num_neighbour':10}
permutations.add_child_hash(rbp_perm, rbp_conf)
......
redis_storage.store_hash_configuration(rbp_perm)
permutations.build_permuted_index()
Finally the result is better than first.
but if I want to run query function ,I cann't remove 'engine.store_vector(vector, data); '.
so how can I only execute query function code, not include store vector codes.
just like,

redis_object = redis.Redis(host='localhost', port=0, db=0, unix_socket_path='/tmp/redis.sock')
redis_storage = RedisStorage(redis_object)
config = redis_storage.load_hash_configuration('v')
if config is None:
rbp_perm = RandomBinaryProjections('v', 30)
else:
rbp_perm = RandomBinaryProjections(None, None)
rbp_perm.apply_config(config)

 engine.candidate_count(query)
 engine.neighbours(query)

I hope you will soon answer my question. ths very much