18. The computer program product of claim 16 , wherein the different threshold values are uniformly distributed within the range.
16. The computer program product of claim 15 , wherein the process further comprises: generating a lookup table having a plurality of cells arranged in rows and columns, each row representing one of the inverted lists and each column representing a different threshold value ranging between zero and a maximum of the squared distances, each cell of the lookup table including a quantity of the data points in the respective inverted list whose squared distance is less than the threshold value corresponding to the column of the cell.