Algorithm 1 Initialization of the Query Result Collection

Input: original node set V = {S1, S2, ..., Sn}, the original data collected by node Si(i = 0, 1, ..., n) Output:TB_qdata table, TB_Sfilters table 1: for ∀ Si ∈ V do { 2: Si normalizes the collected original data 3: Compute and add max, min, reg attributes to form qdata 4: Si sends its qdata tuple to its father node Si+1 5: Si+1 gathers the collected qdata to form the TB_qdata table 6: Fetch the minimum value of max, the minimum value of the attribute min, and the minimum value of the attribute reg of every tuple in the Si+1. TB_qdata table to form the tuple Si+1.filter_tuple 7: Si+1 sends each filter_tuple tuple to its father node Si+2 to form the TB_Sfilters table 8: end for