Encyclopedia of Database Systems

2018 Edition
| Editors: Ling Liu, M. Tamer Özsu

Punctuations

  • David Maier
  • Peter A. Tucker
Reference work entry
DOI: https://doi.org/10.1007/978-1-4614-8265-9_285

Definition

A punctuation is an item embedded in a data stream that specifies a subset of the domain of that stream. A data item that belongs to the subset specified by a punctuation is said to match that punctuation. A data stream is said to be grammatical if, for each punctuation, no data items will follow that match that punctuation. Consider a stream of bids for online auctions. When an auction closes, a punctuation p is embedded in the stream that matches all bids for that auction. In a grammatical stream, p indicates no more bids will arrive from that stream for that auction.

In the most common format, a punctuation is a tuple of patterns, where each pattern corresponds to an attribute of the data items in a stream. Typically, four patterns are used: a wildcard (denoted by ‘*’) is matched by all values, a literal is matched by only the given value, a list (denoted by { }) is matched by any value in the given list, and a range(denoted by [ ]) is matched by any value that falls in...

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Recommended Reading

  1. 1.
    Li J, Maier D, Tufte K, Papadimos V, Tucker PA. Semantics and evaluation techniques for window aggregates in data streams. In: Proceedings of the ACM SIGMOD International Conference on Management of Data; 2005. p. 311–22.zbMATHGoogle Scholar
  2. 2.
    Tucker PA, Maier D, Sheard T, Fegaras L. Exploiting punctuation semantics in continuous data streams. IEEE Trans Knowl Data Eng. 2003;15(3):555–68.CrossRefGoogle Scholar
  3. 3.
    Tucker PA, Maier D, Sheard T, Stephens P. Using punctuation sschemes to characterize strategies for querying over data streams. IEEE Trans Knowl Data Eng. 2007;19(9):1227–40.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Portland State UniversityPortlandUSA
  2. 2.Whitworth UniversitySpokaneUSA

Section editors and affiliations

  • Uĝur Çetintemel
    • 1
  1. 1.Brown UniversityProvidenceUSA