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Structural Decomposition Methods: Key Notions and Database Applications

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A Comprehensive Guide Through the Italian Database Research Over the Last 25 Years

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Abstract

Many difficult problems that are tractable when restricted to acyclic instances are good candidates to be solved efficiently whenever their structure is not precisely acyclic, but not far from that. This is the case for fundamental database problems such as answering conjunctive queries or counting the number of answers (without actually computing them). The chapter describes structural decomposition methods that guarantee tractability for all such problem instances whose associated hypergraphs have a small degree of cyclicity, called width. In particular, it focuses on the notion of hypertree width, by describing its properties and its applications to the database field, and covering queries with aggregate operators and some recent parallel and distributed implementations.

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Notes

  1. 1.

    Some notions strongly related to the treewidth appeared even before the 80’s in the literature. For a detailed story, we refer to [16].

References

  1. C.R. Aberger, S. Tu, K. Olukotun, C. Ré, EmptyHeaded: A relational engine for graph processing, in Proceedings of SIGMOD 2016 (2016)

    Google Scholar 

  2. C.R. Aberger, S. Tu, K. Olukotun, C. Ré, Old techniques for new join algorithms: A case study in RDF processing, in CoRR, arXiv:abs/1602.03557 (2016)

  3. I. Adler, G. Gottlob, M. Grohe, Hypertree width and related hypergraph invariants. Eur. J. Comb. 28(8), 2167–2181 (2007)

    Article  MathSciNet  MATH  Google Scholar 

  4. F.N. Afrati, M. Joglekar, C. Ré, S. Salihoglu, J.D. Ullman, GYM: A multiround join algorithm in mapreduce, in CoRR, arXiv:abs/1410.4156 (2014)

  5. M. Aref, B. ten Cate, T.J. Green, B. Kimelfeld, D. Olteanu, E. Pasalic, T.L. Veldhuizen, G. Washburn, Design and implementation of the logicblox system, in Proceedings of SIGMOD 2015 (2015), pp. 1371–1382

    Google Scholar 

  6. R. Barilaro, F. Ricca, G. Terracina, Optimizing the distributed evaluation of stratified programs via structural analysis, in Proceeding of 11th International Conference on Logic Programming and Nonmonotonic Reasoning (LPNMR 2011), Vancouver, Canada, 2011, Lecture Notes in Computer Science (Springer, Heidelberg, 2011), pp. 217–222

    Google Scholar 

  7. P.A. Bernstein, N. Goodman, Power of natural semijoins. SIAM J. Comput. 10(4), 751–771 (1981)

    Article  MathSciNet  MATH  Google Scholar 

  8. H.L. Bodlaender, A linear time algorithm for finding tree-decompositions of small treewidth, in Proceeding of STOC 1993 (1993), pp. 226–234

    Google Scholar 

  9. A.A. Bulatov, The complexity of the counting constraint satisfaction problem. J. ACM 60(5), 34:1–34:41 (2013)

    MathSciNet  MATH  Google Scholar 

  10. A.A. Bulatov, M. Dyer, L.A. Goldberg, M. Jerrum, C. Mcquillan, The expressibility of functions on the boolean domain, with applications to counting CSPs. J. ACM 60(5), 32:1–32:36 (2013)

    MathSciNet  MATH  Google Scholar 

  11. F. Calimeri, S. Perri, F. Ricca, Experimenting with parallelism for the instantiation of ASP programs. J. Algorithms Cogn. Inf. Log. 63(1–3), 34–54 (2008)

    Article  MathSciNet  MATH  Google Scholar 

  12. H. Chen, S. Mengel, A trichotomy in the complexity of counting answers to conjunctive queries, in Proceeding of ICDT 2015 (2015), pp. 110–126

    Google Scholar 

  13. D.A. Cohen, P. Jeavons, M. Gyssens, A unified theory of structural tractability for constraint satisfaction problems. J. Comput. Syst. Sci. 74(5), 721–743 (2008)

    Article  MathSciNet  MATH  Google Scholar 

  14. V. Dalmau, P. Jonsson, The complexity of counting homomorphisms seen from the other side. Theory Comput. Syst. 329(1–3), 315–323 (2004)

    Article  MathSciNet  MATH  Google Scholar 

  15. J. Dean, S. Ghemawat, Mapreduce: A flexible data processing tool. Commun. ACM 53(1), 72–77 (2010)

    Article  Google Scholar 

  16. R. Dechter, Constraint Processing (Morgan Kaufmann Publishers Inc., 2003)

    Google Scholar 

  17. R. Dechter, N. Flerova, R. Marinescu, Search algorithms for M Best solutions for graphical models, in Proceeding of AAAI 2012 (2012), pp. 1895–1901

    Google Scholar 

  18. R. Fagin, Degrees of acyclicity for hypergraphs and relational database schemes. J. ACM 30(3), 514–550 (1983)

    Article  MathSciNet  MATH  Google Scholar 

  19. W. Fischl, G. Gottlob, R. Pichler, General and fractional hypertree decompositions: Hard and easy cases, in CoRR, arXiv:abs/1611.01090 (2016)

  20. L. Ghionna, L. Granata, G. Greco, F. Scarcello, Hypertree decompositions for query optimization, in Proceeding of ICDE 2007 (2007), pp. 36–45

    Google Scholar 

  21. L. Ghionna, G. Greco, F. Scarcello, H-DB: A hybrid quantitative-structural sql optimizer, in Proceeding of CIKM 2011 (2011), pp. 2573–2576

    Google Scholar 

  22. G. Gottlob, G. Greco, Decomposing combinatorial auctions and set packing problems. J. ACM 60(4), 24:1–24:39 (2013)

    Article  MathSciNet  MATH  Google Scholar 

  23. G. Gottlob, N. Greco, N. Leone, F. Scarcello, Hypertree decompositions: Questions and answers, in Proceeding of PODS 2016 (2016), pp. 57–74

    Google Scholar 

  24. G. Greco, F. Scarcello, Tractable optimization problems through hypergraph-based structural restrictions, in Proceeding of ICALP 2009 (2009), pp. 16–30

    Google Scholar 

  25. G. Gottlob, G. Greco, F. Scarcello, Treewidth and hypertree width, in Tractability: Practical Approaches to Hard Problems, ed. by L. Bordeaux, Y. Hamadi, P. Kohli (2012)

    Google Scholar 

  26. G. Gottlob, M. Grohe, N. Musliu, M. Samer, F. Scarcello, Hypertree decompositions: Structure, algorithms, and applications, in Proceeding of WG 2005 (2005), pp. 1–15

    Google Scholar 

  27. G. Gottlob, S.T. Lee, G. Valiant, P. Valiant, Size and treewidth bounds for conjunctive queries. J. ACM 59(3), 1–35 (2012)

    Article  MathSciNet  MATH  Google Scholar 

  28. G. Gottlob, N. Leone, F. Scarcello, Advanced parallel algorithms for acyclic conjunctive queries. Technical Report DBAI-TR-98/18, Technical University of Vienna (1998)

    Google Scholar 

  29. G. Gottlob, N. Leone, F. Scarcello, On tractable queries and constraints, in Proceeding of DEXA 1999 (1999), pp. 1–15

    Google Scholar 

  30. G. Gottlob, N. Leone, F. Scarcello, The complexity of acyclic conjunctive queries. J. ACM 48(3), 431–498 (2001)

    Article  MathSciNet  MATH  Google Scholar 

  31. G. Gottlob, N. Leone, F. Scarcello, Computing LOGCFL certificates. Theor. Comput. Sci. 270(1–2), 761–777 (2002)

    Article  MathSciNet  MATH  Google Scholar 

  32. G. Gottlob, N. Leone, F. Scarcello, Hypertree decompositions and tractable queries. J. Comput. Syst. Sci. (Conference Version has Appeared in PODS 1999) 64(3), 579–627 (2002)

    MathSciNet  MATH  Google Scholar 

  33. G. Gottlob, N. Leone, F. Scarcello, Robbers, marshals, and guards: Game theoretic and logical characterizations of hypertree width. J. Comput. Syst. Sci. 66(4), 775–808 (2003)

    Article  MathSciNet  MATH  Google Scholar 

  34. G. Gottlob, Z. Miklós, T. Schwentick, Generalized hypertree decompositions: NP-hardness and tractable variants. J. ACM 56(6), 30:1–30:32 (2009)

    Article  MathSciNet  MATH  Google Scholar 

  35. G. Greco, F. Scarcello, The power of tree projections: Local consistency, greedy algorithms, and larger islands of tractability, in Proceeding of PODS 2010 (2010), pp. 327–338

    Google Scholar 

  36. G. Greco, F. Scarcello, Structural tractability of constraint optimization, in Proceeding of CP 2011 (2011), pp. 340–355

    Google Scholar 

  37. G. Greco, F. Scarcello, Counting solutions to conjunctive queries: Structural and hybrid tractability, in Proceeding of PODS 2014 (2014), pp. 132–143

    Google Scholar 

  38. G. Greco, F. Scarcello, Greedy strategies and larger islands of tractability for conjunctive queries and constraint satisfaction problems. Inf. Comput. 252, 201–220 (2017)

    Article  MathSciNet  MATH  Google Scholar 

  39. G. Greco, F. Scarcello, The power of local consistency in conjunctive queries and constraint satisfaction problems. SIAM J. Comput. (2017)

    Google Scholar 

  40. M. Grohe, D. Marx, Constraint solving via fractional edge covers. ACM Trans. Algorithms 11(1), 4:1–4:20 (2014)

    Article  MathSciNet  MATH  Google Scholar 

  41. I.F. Ilyas, G. Beskales, M.A. Soliman, A survey of top-k query processing techniques in relational database systems. ACM Comput. Surv. 40(4), 11:1–11:58 (2008)

    Article  Google Scholar 

  42. M. Joglekar, R. Puttagunta, C. Ré, Aggregations over generalized hypertree decompositions, in Proceeding of PODS 2016 (2016)

    Google Scholar 

  43. M.R. Joglekar, C.M. Ré, It’s all a matter of degree: Using degree information to optimize multiway joins, in Proceeding of ICDT 2016 (2016), pp. 11:1–11:17

    Google Scholar 

  44. O. Kalinsky, Y. Etsion, B. Kimelfeld, Flexible caching in trie joins, in CoRR, arXiv:abs/1602.08721 (2016)

  45. R.M. Karp, V. Ramachandran, Parallel algorithms for shared-memory machines, in Handbook of Theoretical Computer Science, vol. A (MIT Press, 1990), pp. 869–941

    Google Scholar 

  46. K. Kask, R. Dechter, J. Larrosa, A. Dechter, Unifying tree decompositions for reasoning in graphical models. Artif. Intell. 166(1–2), 165–193 (2005)

    Article  MathSciNet  MATH  Google Scholar 

  47. M.A. Khamis, H. Ngo, D. Suciu, Worst-case optimal algorithms for conjunctive queries with functional dependencies, in Proceeding of PODS 2016 (2016)

    Google Scholar 

  48. M.A. Khamis, H.Q. Ngo, C. Ré, A. Rudra, Joins via geometric resolutions: Worst-case and beyond, in Proceeding of PODS 2015 (2015), pp. 213–228

    Google Scholar 

  49. M.A. Khamis, H.Q. Ngo, A. Rudra. FAQ: Questions asked frequently, in Proceedings of PODS 2016 (2016)

    Google Scholar 

  50. B. Kimelfeld, Y. Sagiv, Incrementally computing ordered answers of acyclic conjunctive queries, in Proceedings of NGITS 2006 (2006), pp. 141–152

    Google Scholar 

  51. P.G. Kolaitis, Constraint satisfaction, databases, and logic, in Proceedings of IJCAI 2003 (2003), pp. 1587–1595

    Google Scholar 

  52. E.L. Lawler, A procedure for computing the k best solutions to discrete optimization problems and its application to the shortest path problem. Manag. Sci. 18(7), 401–405 (1972)

    Article  MathSciNet  MATH  Google Scholar 

  53. D. Marx, Approximating fractional hypertree width. ACM Trans. Algorithms 6(2), 29:1–29:17 (2010)

    Article  MathSciNet  MATH  Google Scholar 

  54. D. Marx, Tractable hypergraph properties for constraint satisfaction and conjunctive queries. J. ACM 60(6), 42:1–42:51 (2013)

    Article  MathSciNet  MATH  Google Scholar 

  55. J. Minker (ed.), Foundations of Deductive Databases and Logic Programming (Morgan Kaufmann Publishers Inc., Washington DC, 1988)

    MATH  Google Scholar 

  56. H.Q. Ngo, C. Ré, A. Rudra, Skew strikes back: New developments in the theory of join algorithms. SIGMOD Rec. 42(4), 5–16 (2013)

    Article  Google Scholar 

  57. R. Pichler, S. Skritek, Tractable counting of the answers to conjunctive queries. J. Comput. Syst. Sci. 79(6), 984–1001 (2013)

    Article  MathSciNet  MATH  Google Scholar 

  58. O. Reingold, Undirected connectivity in log-space. J. ACM 55(4), 17:1–17:24 (2008)

    Article  MathSciNet  MATH  Google Scholar 

  59. N. Robertson, P. Seymour, Graph minors. II. Algorithmic aspects of tree-width. J. Algorithms 7(3), 309–322 (1986)

    Article  MathSciNet  MATH  Google Scholar 

  60. F. Scarcello, G. Greco, N. Leone, Weighted hypertree decompositions and optimal query plans. J. Comput. Syst. Sci. 73(3), 475–506 (2007)

    Article  MathSciNet  MATH  Google Scholar 

  61. R.E. Tarjan, M. Yannakakis, Simple linear-time algorithms to test chordality of graphs, test acyclicity of hypergraphs, and selectively reduce acyclic hypergraphs. SIAM J. Comput. 13(3), 566–579 (1984)

    Article  MathSciNet  MATH  Google Scholar 

  62. G. Terracina, N. Leone, V. Lio, C. Panetta, Experimenting with recursive queries in database and logic programming systems. Theory Pract. Log. Program. (TPLP) 8(2), 129–165 (2008)

    Article  MathSciNet  MATH  Google Scholar 

  63. L.G. Valiant, A bridging model for parallel computation. Commun. ACM 33(8), 103–111 (1990)

    Article  Google Scholar 

  64. T.L. Veldhuizen, Triejoin: A simple, worst-case optimal join algorithm, in Proceedings of ICDT 2014 (2014), pp. 96–106

    Google Scholar 

  65. M. Yannakakis, Algorithms for acyclic database schemes, in Proceedings of VLDB 1981 (1981), pp. 82–94

    Google Scholar 

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Acknowledgements

The work was supported by project “Ba2Know (Business Analytics to Know) Service Innovation - LAB”, No. PON03PE_00001_1 funded by the Italian Ministry of University and Research (MIUR), and by project “Smarter Solutions in the Big Data World (S2BDW)”, funded by the Italian Ministry for Economic Development (MISE) within the programme PON “Imprese e competitivitá” 2014–2020.

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Greco, G., Leone, N., Scarcello, F., Terracina, G. (2018). Structural Decomposition Methods: Key Notions and Database Applications. In: Flesca, S., Greco, S., Masciari, E., Saccà, D. (eds) A Comprehensive Guide Through the Italian Database Research Over the Last 25 Years. Studies in Big Data, vol 31. Springer, Cham. https://doi.org/10.1007/978-3-319-61893-7_15

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