Andrew McGregor, A. Pavan, et al.
Algorithmica
We present a simple, message-optimal algorithm for maintaining a random sample from a large data stream whose input elements are distributed across multiple sites that communicate via a central coordinator. At any point in time, the set of elements held by the coordinator represent a uniform random sample from the set of all the elements observed so far. When compared with prior work, our algorithms asymptotically improve the total number of messages sent in the system. We present a matching lower bound, showing that our protocol sends the optimal number of messages up to a constant factor with large probability. We also consider the important case when the distribution of elements across different sites is non-uniform, and show that for such inputs, our algorithm significantly outperforms prior solutions.
Andrew McGregor, A. Pavan, et al.
Algorithmica
Kenneth L. Clarkson, Elad Hazan, et al.
Journal of the ACM
T.S. Jayram, David P. Woodruff
FOCS 2009
Maria-Florina Balcan, Yingyu Liang, et al.
KDD 2016