Partitioning oracles were introduced by Hassidim et al. (FOCS 2009) as a
generic tool for constant-time algorithms. For any epsilon > 0, a partitioning
oracle provides query access to a fixed partition of the input bounded-degree
minor-free graph, in which every component has size poly(1/epsilon), and the
number of edges removed is at most epsilon*n, where n is the number of vertices
in the graph.
In STOC'05, Indyk and Woodruff introduced a new technique that yielded a
near-optimal space algorithm for $F_k$ moment estimation problem. Since then,
the technique has inspired a number of advances in streaming algorithmics. We
show that at least several of these results follow easily from the application
of a single probabilistic technique, called Precision Sampling. Using it, we
obtain simple streaming algorithms that maintain a randomized sketch of an
input vector $x=(x_1,...,x_n)$, useful for the following applications:
Estimating the $F_k$ moment of $x$, for $k>2$.
We consider the problem of testing distribution identity. Given a sequence of
independent samples from an unknown distribution on a domain of size n, the
goal is to check if the unknown distribution approximately equals a known
distribution on the same domain. While Batu, Fortnow, Fischer, Kumar,
Rubinfeld, and White (FOCS 2001) proved that the sample complexity of the
problem is O~(sqrt(n) * poly(1/epsilon)), the running time of their tester is
much higher: O(n) + O~(sqrt(n) * poly(1/epsilon)). We modify their tester to
achieve a running time of O~(sqrt(n) * poly(1/epsilon)).