Abstract: A method for querying in a candidate vector set candidate vectors similar to object vectors is disclosed, wherein the candidate vector set comprises a plurality of candidate vectors each being quantized as having a central vector portion and a residual vector portion, and the candidate vector set comprises a plurality of candidate vector subsets, the method comprising: acquiring a set of object vectors; querying, for each object vector of the set of object vectors, a first number of candidate vector subsets that are closest to the object vector; generating and storing a plurality of common calculation results based on a set of central vector portions and a set of residual vector portions of candidate vectors of the first number of candidate vector subsets; generating and storing pre-calculation results based on the set of object vectors and the set of residual vector portion; and determining, for each object vector of the set of object vectors, a second number of candidate vectors that are similar to the obje