Soft Cardinality Constaints on XML Data

Soft Cardinality Constraints on XML Data, How Exceptions Prove the Business Rule. Research Paper at WISE 2013, Nanjing, China, 14th October 2013.

Transcript

1. Soft Cardinality Constraints on XML Data How Exceptions Prove the Business Rule Emir Muñoz Fujitsu Ireland Ltd. Joint work with F. Ferrarotti, S. Hartmann, S. Link, M. Marin @ Nanjing, China, 14th October 2013
2. Contribution • Introduce the definition of soft cardinality constraints over XML data. • Efficient low-degree polynomial time decision algorithm for the implication problem. • Empirical evaluation of soft cardinality constraints on real XML data. Emir M. - WISE, Nanjing, China, 14th October 2013 2
3. Outline 1. Introduction 2. Soft Cardinality Constraints 3. The Implication Problem 4. Performance Evaluation 5. Conclusion Emir M. - WISE, Nanjing, China, 14th October 2013 3
4. Introduction Concepts • Cardinality constraints: – Capture information about the frequency with which certain data items occur in particular context. • Soft cardinality constraints: – Constraints which need to be satisfied on average only, and thus permit violations in a controlled manner. Emir M. - WISE, Nanjing, China, 14th October 2013 4
5. Introduction Example (1/2) Emir M. - WISE, Nanjing, China, 14th October 2013 5 Project within a research institute support research
6. • Some cardinality constraints: – Every scientist is a member of 2, 3, or 4 research teams. – Every technician can work in up to 4 different support teams. – A project cannot have more than one manager. – In every team, there should be two employees for each expertise level. Emir M. - WISE, Nanjing, China, 14th October 2013 6 Introduction Example (2/2)
7. • Some cardinality constraints: – Every scientist is a member of 2, 3, or 4 research teams. – Every technician can work in up to 4 different support teams. – A project cannot have more than one manager. – In every team, there should be two employees for each expertise level. Emir M. - WISE, Nanjing, China, 14th October 2013 7 Introduction Example (2/2) Probably will be exceptions Scientist working in 5 research teams or more Soft constraints
8. Soft Cardinality Constraints Definition • Expressiveness from the ability to specify soft upper bounds (soft-max) as well as soft lower bounds (soft-min) on the number of nodes. • soft-card(Q, (Q´, {Q1,…, Qk})) = (soft-min, soft-max) • With some sources of intractability Emir M. - WISE, Nanjing, China, 14th October 2013 8 Context path Target path Field paths soft-min = 1
9. • Every scientist is a member of 2, 3, or 4 research teams. – soft-card(ε, (_.RTeam.Sci, {id})) = (2, 4) • Every technician can work in up to 4 different support teams. – soft-card(ε, (_.STeam.Tech, {id})) = (1, 4) • A project cannot have more than one manager. – soft-card(_, (Manager, Ø)) = (1, 1) • In every team, there should be two employees for each expertise level. – soft-card(_._, (_, {Expertise.S})) = (2, 2) Emir M. - WISE, Nanjing, China, 14th October 2013 9 Soft Cardinality Constraints Examples
10. The Implication Problem Definition and Algorithm • Let be a finite set of (soft) constraints. • We say that finitely implies , denoted by if every finite XML T that satisfies all also satisfies Emir M. - WISE, Nanjing, China, 14th October 2013 10
11. Performance Evaluation Configuration • We compare the performance against XML Keys • Machine Intel Core i7 2.8GHz, with 4G RAM • Documents: – 321gone, yahoo (auction data) – dblp (bibliographic information on CS) – nasa (astronomical data) – SigmodRecord (articles from SIGMOD Record) – mondial (world geographic db) Emir M. - WISE, Nanjing, China, 14th October 2013 11
12. Performance Evaluation Results Expressivity Time Emir M. - WISE, Nanjing, China, 14th October 2013 12 In comparison with previous XML keys
13. Conclusion • We introduced an expressive class of soft cardinality constraints, sufficiently flexible to boost XML applications such as data exchange and integration. • Slight extensions result in the intractability of the associated implication problem. • We give an axiomatization for this new class. • Present an empirical performance test that indicate its efficient application in real use cases. Emir M. - WISE, Nanjing, China, 14th October 2013 13
14. Discussion • Questions & Answers – Soft Cardinality Constraints on XML Data THANKS! Emir Muñoz emir@emunoz.org Emir M. - WISE, Nanjing, China, 14th October 2013 14