Streaming algorithm
This is the process of data streaming with less memory. x∈R^n This is high dimensional vector. You update it. xi←xi+v You have O(n) space, and the whole stream is O(m). You compress the data by streaming . A=(1±ε)B (1-ε)B≦A≦(1+ε)B ∴ σi,j = ±1, E[σi,j] = 0