Skip to main content
SpringerLink
Log in
Book cover

Encyclopedia of Database Systems pp 2659–2664Cite as

Snapshot Isolation

  • Reference work entry

Synonyms

SI; Row-versioning

Definition

Snapshot Isolation is a multi-version concurrency control approach that is widely used in practice. A transaction T that operates under Snapshot Isolation never observes any effects from other transactions that overlap T in duration; instead T sees values as if it were operating on a private copy or snapshot of the database, reflecting all other transactions that had committed before Tstarted. In Snapshot Isolation, the system will not allow both of two transactions to commit if they overlap in duration and modify the same data item. Snapshot Isolation prevents many well-known anomalies (such as Lost Updates and Inconsistent Reads) that are also prevented by Serializability, but it does not guarantee that all executions will be Serializable. Snapshot Isolation allows reads to occur without delay or blocking caused by concurrent updates, and also updates are never blocked by concurrent readers, so Snapshot Isolation often gives the transactions...

This is a preview of subscription content, log in via an institution.

Chapter
USD   29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
eBook
USD   2,500.00
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever

Tax calculation will be finalised at checkout

Purchases are for personal use only

Learn about institutional subscriptions

Recommended Reading

  1. Adya A. Weak consistency: a generalized theory and optimistic implementations for distributed transactions (PhD thesis). Technical Report MIT/LCS/TR-786, Laboratory for Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA, 1999.

    Google Scholar 

  2. Berenson H., Bernstein P.A., Gray J., Melton J., O’Neil E.J., and O’Neil P.E. A critique of ANSI SQL isolation levels. In Proc. ACM SIGMOD Int. Conf. on Management of Data, 1995, pp. 1–10.

    Google Scholar 

  3. Bernstein A.J., Lewis P.M., and Lu S. Semantic conditions for correctness at different isolation levels. In Proc. 16th Int. Conf. on Data Engineering, 2000, pp. 57–66.

    Google Scholar 

  4. Chan A., Fox S., Lin W.-T.K., Nori A., and Ries D.R. The implementation of an integrated concurrency control and recovery scheme. In Proc. ACM SIGMOD Int. Conf. on Management of Data, 1982, pp. 184–191.

    Google Scholar 

  5. Daudjee K. and Salem K. Lazy database replication with snapshot isolation. In Proc. 32nd Int. Conf. on Very Large Data Bases, 2006, pp. 715–726.

    Google Scholar 

  6. Elnikety S., Zwaenepoel W., and Pedone F. Database replication using generalized snapshot isolation. In Proc. 24th IEEE Symp. on Reliable Dist. Syst., 2005, pp. 73–84.

    Google Scholar 

  7. Fekete A. Allocating isolation levels to transactions. In Proc. 24th ACM SIGACT-SIGMOD-SIGART Symp. on Principles of Database Systems, 2005, pp. 206–215.

    Google Scholar 

  8. Fekete A., Liarokapis D., O’Neil E., O’Neil P., and Shasha D. Making snapshot isolation serializable. ACM Trans. Database Syst., 30(2):492–528, 2005.

    Google Scholar 

  9. Jacobs K. Concurrency control: transaction isolation and serializability in SQL92 and Oracle7. Technical Report A33745 (White Paper), Oracle Corporation, 1995.

    Google Scholar 

  10. Jorwekar S., Fekete A., Ramamritham K., and Sudarshan S. Automating the detection of snapshot isolation anomalies. In Proc. 33rd Int. Conf. on Very Large Data Bases, 2007, pp. 1263–1274.

    Google Scholar 

  11. Lin Y., Kemme B., Patiño-Martínez M., and Jiménez-Peris R. Middleware based data replication providing snapshot isolation. In Proc. ACM SIGMOD Int. Conf. on Management of Data, 2005, pp. 419–430.

    Google Scholar 

  12. Plattner C. and Alonso G. Ganymed: scalable replication for transactional web applications. In Proc. ACM/IFIP/USENIX Int. Middleware Conf., 2004, pp. 155–174.

    Google Scholar 

  13. Schenkel R. and Weikum G. Integrating snapshot isolation into ransactional federation. In Proc. Int. Conf. on Cooperative Inf. Syst., 2000, pp. 90–101.

    Google Scholar 

  14. Transaction Processing Performance Council. TPC Benchmark C Standard Specification, Revision 5.0. 2001. URL: http://www.tpc.org/tpcc/

  15. Weikum G. and Vossen G. Transactional information systems: Theory, algorithms, and the practice of concurrency control and recovery. Morgan Kaufmann, Los Altos, CA, USA, 2002.

    Google Scholar 

  16. Wu S. and Kemme B. Postgres-R(SI): combining replica control with concurrency control based on snapshot isolation. In Proc. 21st Int. Conf. on Data Engineering, 2005, pp. 422–433.

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. University of Sydney, Sydney, NSW, Australia

    Alan Fekete

Authors
  1. Alan Fekete
    View author publications

    You can also search for this author in PubMed Google Scholar

Editor information

Editors and Affiliations

  1. College of Computing, Georgia Institute of Technology, 266 Ferst Drive, 30332-0765, Atlanta, GA, USA

    LING LIU (Professor) (Professor)

  2. Database Research Group David R. Cheriton School of Computer Science, University of Waterloo, 200 University Avenue West, N2L 3G1, Waterloo, ON, Canada

    M. TAMER ÖZSU (Professor and Director, University Research Chair) (Professor and Director, University Research Chair)

Rights and permissions

Reprints and permissions

Copyright information

© 2009 Springer Science+Business Media, LLC

About this entry

Cite this entry

Fekete, A. (2009). Snapshot Isolation. In: LIU, L., ÖZSU, M.T. (eds) Encyclopedia of Database Systems. Springer, Boston, MA. https://doi.org/10.1007/978-0-387-39940-9_346

Download citation

Publish with us

Policies and ethics

Search

Navigation