Editing Open Problems:13

{{DISPLAYTITLE:Problem 13: Effects of Subsampling}}
{{Infobox
|label1 = Proposed by
|data1 = Yossi Matias
|label2 = Source
|data2 = [[Workshops:Kanpur_2006|Kanpur 2006]]
|label3 = Short link
|data3 = http://sublinear.info/13
}}
When processing very fast streams, it is not feasible to run a streaming algorithm on the entire stream, even one that can process each element in $O(1)$ time. Rather it is necessary to sample from the stream and to process the sub-stream using a streaming algorithm. For standard problems such as estimating $F_0$, how does the sub-sampling affect that the accuracy of the streaming algorithms? How should the sampling rate and the per-element time-complexity of a streaming algorithm be traded-off to achieve optimal results? 

Another way to formalize this question, suggested by Muthukrishnan, is
in terms of what part of the stream to skip and which to stream.
A formal definition of the model and algorithms for estimating $F_2$ and others can be found in 
{{cite|BhattacharyyaMMY-07}}.