Range Efficient Computation of F0 over Massive Data Streams

Efficient one-pass computation of F0, the number of distinct elements in a data stream, is a fundamental problem arising in various contexts in databases and networking. We consider the problem of efficiently estimating F0 of a data stream where each element of the stream is an interval of integers. We present a randomized algorithm which gives an ( , ) approximation of F0, with the following time complexity (n is the size of the universe of the items): (1)The amortized processing time per interval is O(log 1 log n ). (2)The time to answer a query for F0 is O(log 1/). The workspace used is O( 1 2 log 1 log n) bits. Our algorithm improves upon a previous algorithm by Bar-Yossef, Kumar and Sivakumar [5], which requires O( 1 5 log 1 log5 n) processing time per item. Our algorithm can be used to compute the max-dominance norm of a stream of multiple signals, and significantly improves upon the current best bounds due to Cormode and Muthukrishnan [11]. This also provides efficient and nove...

• Type: Conference
• Year: 2005
• Where: ICDE
• Authors: Pavan Aduri, Srikanta Tirthapura
• Keywords: Data Stream, Database, Efficient One-pass Computation, ICDE 2005, Randomized Algorithm