Encyclopedia of Database Systems

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


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


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...

This is a preview of subscription content, log in to check access.

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