Achieving a Sequenced, Relational Query Language with Log-Segmented Timestamps

Authors Curtis E. Dyreson , M. A. Manazir Ahsan



PDF
Thumbnail PDF

File

LIPIcs.TIME.2021.14.pdf
  • Filesize: 0.72 MB
  • 13 pages

Document Identifiers

Author Details

Curtis E. Dyreson
  • Department of Computer Science, Utah State University, Logan, UT, USA
M. A. Manazir Ahsan
  • Department of Computer Science, Utah State University, Logan, UT, USA

Acknowledgements

The open access publication of this article was supported by the Alpen-Adria-Universität Klagenfurt, Austria.

Cite AsGet BibTex

Curtis E. Dyreson and M. A. Manazir Ahsan. Achieving a Sequenced, Relational Query Language with Log-Segmented Timestamps. In 28th International Symposium on Temporal Representation and Reasoning (TIME 2021). Leibniz International Proceedings in Informatics (LIPIcs), Volume 206, pp. 14:1-14:13, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2021)
https://doi.org/10.4230/LIPIcs.TIME.2021.14

Abstract

In a period-timestamped, relational temporal database, each tuple is timestamped with a period. The timestamp records when the tuple is "alive" in some temporal dimension. Sequenced semantics is a special semantics for evaluating a query in a temporal database. The semantics stipulates that the query must, in effect, be evaluated simultaneously in each time instant using the tuples alive at that instant. Previous research has proposed changes to the query evaluation engine to support sequenced semantics. In this paper we show how to achieve sequenced semantics without modifying a query evaluation engine. Our technique has two pillars. First we use log-segmented timestamps to record a tuple’s lifetime. A log-segmented timestamp divides the time-line into segments of known length. Any temporal period can be represented by a small number of such segments. Second, by taking advantage of the properties of log-segmented timestamps, we translate a sequenced relational algebra query to a non-temporal relational algebra query, using the operations already present in an unmodified, non-temporal query evaluation engine. The primary contribution of this paper is how to implement sequenced semantics using log-segmented timestamped tuples in a generic DBMS, which, to the best of our knowledge, has not been previously shown.

Subject Classification

ACM Subject Classification
  • Information systems → Temporal data
  • Information systems → Relational database query languages
Keywords
  • Temporal databases
  • sequenced semantics
  • query evaluation
  • relational algebra

Metrics

  • Access Statistics
  • Total Accesses (updated on a weekly basis)
    0
    PDF Downloads

References

  1. Michael H. Böhlen. Temporal coalescing. In Encyclopedia of Database Systems, pages 2932-2936. Springer, 2009. URL: https://doi.org/10.1007/978-0-387-39940-9_388.
  2. Michael H. Böhlen and Christian S. Jensen. Sequenced semantics. In Ling Liu and M. Tamer Özsu, editors, Encyclopedia of Database Systems, Second Edition. Springer, 2018. URL: https://doi.org/10.1007/978-1-4614-8265-9_1053.
  3. Michael H. Böhlen, Christian S. Jensen, and Richard T. Snodgrass. Nonsequenced semantics. In Ling Liu and M. Tamer Özsu, editors, Encyclopedia of Database Systems, Second Edition. Springer, 2018. URL: https://doi.org/10.1007/978-1-4614-8265-9_1052.
  4. Cindy Xinmin Chen and Carlo Zaniolo. Sql^st: A spatio-temporal data model and query language. In ER, pages 96-111, 2000. URL: https://doi.org/10.1007/3-540-45393-8_8.
  5. Jan Chomicki and David Toman. Abstract versus concrete temporal query languages. In Encyclopedia of Database Systems, pages 1-6. Springer, 2009. URL: https://doi.org/10.1007/978-0-387-39940-9_1559.
  6. George Christodoulou, Panagiotis Bouros, and Nikos Mamoulis. Hint: A hierarchical index for intervals in main memory, 2021. URL: http://arxiv.org/abs/2104.10939.
  7. Anton Dignös, Michael H. Böhlen, and Johann Gamper. Temporal Alignment. In SIGMOD, pages 433-444, 2012. URL: https://doi.org/10.1145/2213836.2213886.
  8. Curtis E. Dyreson. Observing Transaction-Time Semantics with TTXPath. In WISE (1), pages 193-202, 2001. URL: https://doi.org/10.1109/WISE.2001.996480.
  9. Curtis E. Dyreson. Using couchdb to compute temporal aggregates. In 18th IEEE International Conference on High Performance Computing and Communications; 14th IEEE International Conference on Smart City; 2nd IEEE International Conference on Data Science and Systems, HPCC/SmartCity/DSS 2016, Sydney, Australia, December 12-14, 2016, pages 1131-1138. IEEE Computer Society, 2016. URL: https://doi.org/10.1109/HPCC-SmartCity-DSS.2016.0159.
  10. Curtis E. Dyreson and Venkata A. Rani. Translating temporal SQL to nested SQL. In Curtis E. Dyreson, Michael R. Hansen, and Luke Hunsberger, editors, 23rd International Symposium on Temporal Representation and Reasoning, TIME 2016, Kongens Lyngby, Denmark, October 17-19, 2016, pages 157-166. IEEE Computer Society, 2016. URL: https://doi.org/10.1109/TIME.2016.24.
  11. Curtis E. Dyreson, Venkata A. Rani, and Amani Shatnawi. Unifying sequenced and non-sequenced semantics. In Fabio Grandi, Martin Lange, and Alessio Lomuscio, editors, 22nd International Symposium on Temporal Representation and Reasoning, TIME 2015, Kassel, Germany, September 23-25, 2015, pages 38-46. IEEE Computer Society, 2015. URL: https://doi.org/10.1109/TIME.2015.22.
  12. Curtis E. Dyreson and Richard T. Snodgrass. Timestamp semantics and representation. Inf. Syst., 18(3):143-166, 1993. URL: https://doi.org/10.1016/0306-4379(93)90034-X.
  13. Fabio Grandi. T-SPARQL: A TSQL2-like Temporal Query Language for RDF. In ADBIS, pages 21-30, 2010. URL: http://ceur-ws.org/Vol-639/021-grandi.pdf.
  14. C. S. Jensen and C. E. Dyreson (editors). A Consensus Glossary of Temporal Database Concepts - February 1998 Version. In Temporal Databases: Research and Practice, Lecture Notes in Computer Science 1399, pages 367-405. Springer-Verlag, 1998. Google Scholar
  15. R. T. Snodgrass. Introduction to TSQL2. In R. T. Snodgrass, editor, The TSQL2 Temporal Query Language, chapter 2, pages 19-31. Kluwer Academic Publishers, 1995. Google Scholar
  16. Richard T. Snodgrass. The Temporal Query Language TQuel. ACM Trans. Database Syst., 12(2):247-298, 1987. URL: https://doi.org/10.1145/22952.22956.
  17. Richard T. Snodgrass, editor. The TSQL2 Temporal Query Language. Kluwer, 1995. Google Scholar
  18. A. U. Tansel. Modelling temporal data. Information and Software Technology, 32(8):514-520, October 1990. Google Scholar
  19. Kristian Torp, Christian S. Jensen, and Michael H. Böhlen. Layered temporal DBMS: concepts and techniques. In DASFAA, pages 371-380, 1997. Google Scholar
  20. Kristian Torp, Christian S. Jensen, and Richard T. Snodgrass. Stratum Approaches to Temporal DBMS Implementation. In IDEAS, pages 4-13, 1998. URL: https://doi.org/10.1109/IDEAS.1998.694346.
Questions / Remarks / Feedback
X

Feedback for Dagstuhl Publishing


Thanks for your feedback!

Feedback submitted

Could not send message

Please try again later or send an E-mail