Abstract
Continuous queries are persistent queries that allow users to receive new results when they become available. While continuous query systems can transform a passive web into an active environment, they need to be able to support millions of queries due to the scale of the Internet. No existing systems have achieved this level of scalability. NiagaraCQ addresses this problem by grouping continuous queries based on the observation that many web queries share similar structures. Grouped queries can share the common computation, tend to fit in memory and can reduce the I/O cost significantly. Furthermore, grouping on selection predicates can eliminate a large number of unnecessary query invocations. Our grouping technique is distinguished from previous group optimization approaches in the following ways. First, we use an incremental group optimization strategy with dynamic re-grouping. New queries are added to existing query groups, without having to regroup already installed queries. Second, we use a query-split scheme that requires minimal changes to a general-purpose query engine. Third, NiagaraCQ groups both change-based and timer-based queries in a uniform way. To insure that NiagaraCQ is scalable, we have also employed other techniques including incremental evaluation of continuous queries, use of both pull and push models for detecting heterogeneous data source changes, and memory caching. This paper presents the design of NiagaraCQ system and gives some experimental results on the system's performance and scalability.
- CM86 U.S. Chakravarthy and J. Minker. Multiple Query Processing in Deductive Databases using Query Graphs. VLDB Conference 1986: 384-391. Google ScholarDigital Library
- DFF+98 A. Deutsch, M. Fernandez, D. Florescu, A. Levy, D. Suciu. XML-QL: A Query Langaage for XML. http://www.w3.org/TR/NOTE-xml-ql.Google Scholar
- HCH+99 E. N. Hanson, C. Carnes, L. Huang, M. Konyala, L. Noronha, S. Parthasarathy, J.B.Park and A. Vernon. Scalable Trigger Processing. In proceeding of 15 th ICDE, page 266-275, Sydney, Australia, 1999. Google ScholarDigital Library
- HJ94 E. N. Hanson and T. Johnson. Selection Predicate Indexing for Active Databases Using Interval Skip List. TR94-017. CIS department, University of Florida, 1994.Google Scholar
- LPBZ96 L. Liu, C. Pu, R. Barga, T. Zhou. Differential Evaluation of Continual Queries. ICDCS 1996: 458-465. Google ScholarDigital Library
- LPT99 L. Liu, C. Pu, W. Tang. Continual Queries for Internet Scale Event-Driven Information Delivery. TKDE 11(4): 610-628 (1999). Google ScholarDigital Library
- MD89 D. McCarthy and U. Dayal. The architecture of an active database management system. SIGMOD 1989: 215-224. Google ScholarDigital Library
- RC88 A. Rosenthal and U. S. Chakravarthy. Anatomy of a Modular Multiple Query Optimizer. VLDB 1988: 230-239. Google ScholarDigital Library
- Sel86 T. Sellis. Multiple query optimization. ACM Transactions on Database Systems, 10(3), 1986.Google Scholar
- SJGP90 M. Stonebraker, A. Jhingran, J. Goh and S. Potamianos. On Rules, Procedures, Caching and Views in Data Base Systems. SIGMOD Conference 1990: 281-290. Google ScholarDigital Library
- SK95 E. Simon, A. Kotz-Dittrich. Promises and Realities of Active Database Systems. VLDB 1995: 642-653. Google ScholarDigital Library
- SPAM91 U. Schreier, H. Pirahesh, R. Agrawal, and C. Mohan. Alert: An architecture for transforming a passive dbms into an active dbms. VLDB 1991: 469-478. Google ScholarDigital Library
- TGNO92 D. Terry, D. Goldberg, D. Nichols, and B. Oki. Continuous Queries over Append-Only Databases. SIGMOD 1992: 321-330. Google ScholarDigital Library
- WF89 J. Widom and S.J. Finklestein. Set-Oriented Production Rules in Relational Database Systems. SIGMOD Conference 1990: 259-270. Google ScholarDigital Library
- ZDNS98 Y. Zhao, P. Deshpande, J. F. Naughton, A. Shukla. Simultaneous Optimization and Evaluation of Multiple Dimensional Queries. SIGMOD 1998: 271-282. Google ScholarDigital Library
Index Terms
- NiagaraCQ: a scalable continuous query system for Internet databases
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