• Publications
  • Influence
Query optimization for parallel execution
The decreasing cost of computing makes it economically viable to reduce the response time of decision support queries by using parallel execution to exploit inexpensive resources. Expand
Simpler algorithm for estimating frequency moments of data streams
The problem of estimating the <i>k</i><sup><i>th</i></sup> frequency moment of a data stream by looking at the items exactly once as they arrive was posed in [1, 2]. Expand
Bifocal sampling for skew-resistant join size estimation
This paper introduces bifocal sampling, a new technique for estimating the size of an equi-join of two relations based on the number of tuples with the same join value. Expand
Estimating Entropy over Data Streams
We present an algorithm for estimating entropy of data streams consisting of insertion and deletion operations using space Õ(1) space. Expand
On Estimating Frequency Moments of Data Streams
Space-economical estimation of the pth frequency moments, defined as , for p> 0, are of interest in estimating all-pairs distances in a large data matrix [14]. Expand
Parallel Bottom-Up Processing of Datalog Queries
We introduce the notion of a discriminating predicate, based on hash functions, that partitions the computation between the processors in order to achieve parallelism. Expand
Counting distinct items over update streams
  • S. Ganguly
  • Computer Science, Mathematics
  • Theor. Comput. Sci.
  • 20 June 2007
In data streaming applications, data arrives at rapid rates and in high volume, thus making it essential to process each stream update very efficiently. Expand
Tracking set-expression cardinalities over continuous update streams
In this paper, we propose the first space-efficient algorithmic solution for estimating the cardinality of full-fledged set expressions over general update streams. Expand
Estimating Frequency Moments of Data Streams Using Random Linear Combinations
  • S. Ganguly
  • Mathematics, Computer Science
  • 22 August 2004
The problem of estimating the k th frequency moment F k for any non-negative k, over a data stream by looking at the items exactly once as they arrive, was considered in a seminal paper by Alon, Matias and Szegedy [1,2]. Expand
Optimizing View Queries in ROLEX to Support Navigable Result Trees
The ROLEX query optimizer uses a characterization of the navigation behavior of an application, and optimizes view queries to minimize the expected cost of that navigation. Expand