Abstract.
We consider the problem of estimating hybrid frequency moments of two dimensional data
streams. In this model, data is viewed to be organized in a matrix form (Ai;j)1i;j;n. The entries
Ai;j are updated coordinate-wise, in arbitrary order and possibly multiple times. The updates include
both increments and decrements to the current value of Ai;j . The hybrid frequency moment Fp;q(A)
is dened as
Pn
j=1