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A synopsis of dataset D is an abstract of D. A sketch is also referred to an abstract of dataset D but is usually referred to an abstract in a sampling method.
Key Points
Sketch/synopsis techniques have many applications. They are mainly used for statistics estimation in query processing optimization and for supporting on-line data analysis via approximate query processing. The goal is to develop effective and efficient techniques to build a small space synopsis while achieving high precision. For instance, a key component in query processing optimization is to estimate the result sizes of queries. Many techniques [1,2] have been developed for this purpose, including histograms, wavelets, and join synopses.
In data stream applications, the space requirements of synopses/sketches are critical to keep them in memory for on-line query processing. Streams are usually massive in size and fast at arrival rates; consequently it may be infeasible to keep a whole...
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Recommended Reading
Alon N., Gibbons P.B., Matias Y., and Szegedy M. Tracking join and self-join sizes in limited storage. In Proc. 18th ACM SIGMOD-SIGACT-SIGART Symposium on Principles of Database Systems, 1999.
Gibbons P.B. and Matias Y. Synopsis data structures for massive data sets. In Proc. ACM-SIAM Symposium on Discrete Algorithms, 1999.
Zhang Y., Lin X., Xu J., Korn F., and Wang W. Space-efficient relative error order sketch over data streams. In Proc. 22nd Int. Conf. on Data Engineering, 2006.
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© 2009 Springer Science+Business Media, LLC
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Lin, X. (2009). Data Sketch/Synopsis. In: LIU, L., ÖZSU, M.T. (eds) Encyclopedia of Database Systems. Springer, Boston, MA. https://doi.org/10.1007/978-0-387-39940-9_549
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DOI: https://doi.org/10.1007/978-0-387-39940-9_549
Publisher Name: Springer, Boston, MA
Print ISBN: 978-0-387-35544-3
Online ISBN: 978-0-387-39940-9
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