Title
Semantics and evaluation techniques for window aggregates in data streams
Abstract
A windowed query operator breaks a data stream into possibly overlapping subsets of data and computes a result over each. Many stream systems can evaluate window aggregate queries. However, current stream systems suffer from a lack of an explicit definition of window semantics. As a result, their implementations unnecessarily confuse window definition with physical stream properties. This confusion complicates the stream system, and even worse, can hurt performance both in terms of memory usage and execution time. To address this problem, we propose a framework for defining window semantics, which can be used to express almost all types of windows of which we are aware, and which is easily extensible to other types of windows that may occur in the future. Based on this definition, we explore a one-pass query evaluation strategy, the Window-ID (WID) approach, for various types of window aggregate queries. WID significantly reduces both required memory space and execution time for a large class of window definitions. In addition, WID can leverage punctuations to gracefully handle disorder. Our experimental study shows that WID has better execution-time performance than existing window aggregate query evaluation options that retain and reprocess tuples, and has better latency-accuracy tradeoffs for disordered input streams compared to using a fixed delay for handling disorder.
Year
DOI
Venue
2005
10.1145/1066157.1066193
SIGMOD Conference
Keywords
Field
DocType
defining window semantics,execution time,current stream system,window semantics,evaluation technique,disordered input stream,window aggregate query,stream system,window aggregate query evaluation,window definition,data stream,navigation,information retrieval,metadata
Data mining,Evaluation strategy,Metadata,Data stream mining,Data stream,Tuple,Computer science,Implementation,Operator (computer programming),Database,Semantics
Conference
ISBN
Citations 
PageRank 
1-59593-060-4
101
3.83
References 
Authors
12
5
Search Limit
100101
Name
Order
Citations
PageRank
Jin Li129911.91
David Maier256391666.90
Kristin Tufte31241146.09
Vassilis Papadimos440517.65
pete tucker535116.29