Title
Estimating small moments of data stream in nearly optimal space-time
Abstract
For each $p \in (0,2]$, we present a randomized algorithm that returns an $\epsilon$-approximation of the $p$th frequency moment of a data stream $F_p = \sum_{i = 1}^n \abs{f_i}^p$. The algorithm requires space $O(\epsilon^{-2} \log (mM)(\log n))$ and processes each stream update using time $O((\log n) (\log \epsilon^{-1}))$. It is nearly optimal in terms of space (lower bound $O(\epsilon^{-2} \log (mM))$ as well as time and is the first algorithm with these properties. The technique separates heavy hitters from the remaining items in the stream using an appropriate threshold and estimates the contribution of the heavy hitters and the light elements to $F_p$ separately. A key component is the design of an unbiased estimator for $\abs{f_i}^p$ whose data structure has low update time and low variance.
Year
Venue
Keywords
2010
Clinical Orthopaedics and Related Research
space time,lower bound,unbiased estimator,randomized algorithm,data structure
Field
DocType
Volume
Space time,Randomized algorithm,Discrete mathematics,Binary logarithm,Data structure,Combinatorics,Data stream,Upper and lower bounds,Bias of an estimator,Mathematics
Journal
abs/1005.1
Citations 
PageRank 
References 
0
0.34
0
Authors
1
Name
Order
Citations
PageRank
Sumit Ganguly1813236.01