{"id":"https://openalex.org/W1988026822","doi":"https://doi.org/10.1145/2448496.2448508","title":"Structural tractability of counting of solutions to conjunctive queries","display_name":"Structural tractability of counting of solutions to conjunctive queries","publication_year":2013,"publication_date":"2013-03-18","ids":{"openalex":"https://openalex.org/W1988026822","doi":"https://doi.org/10.1145/2448496.2448508","mag":"1988026822"},"language":"en","primary_location":{"id":"doi:10.1145/2448496.2448508","is_oa":false,"landing_page_url":"https://doi.org/10.1145/2448496.2448508","pdf_url":null,"source":null,"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Proceedings of the 16th International Conference on Database Theory","raw_type":"proceedings-article"},"type":"conference-paper","indexed_in":["crossref"],"open_access":{"is_oa":false,"oa_status":"closed","oa_url":null,"any_repository_has_fulltext":false},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5059509786","display_name":"Arnaud Durand","orcid":"https://orcid.org/0000-0002-7629-2121"},"institutions":[{"id":"https://openalex.org/I169173203","display_name":"D\u00e9l\u00e9gation Paris 7","ror":"https://ror.org/00bw5n526","country_code":"FR","type":"government","lineage":["https://openalex.org/I154526488","https://openalex.org/I169173203"]},{"id":"https://openalex.org/I204730241","display_name":"Universit\u00e9 Paris Cit\u00e9","ror":"https://ror.org/05f82e368","country_code":"FR","type":"education","lineage":["https://openalex.org/I204730241"]}],"countries":["FR"],"is_corresponding":false,"raw_author_name":"Arnaud Durand","raw_affiliation_strings":["Logique Universit\u00e9 Paris Diderot Paris, France"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Logique Universit\u00e9 Paris Diderot Paris, France","institution_ids":["https://openalex.org/I169173203","https://openalex.org/I204730241"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5108117955","display_name":"Stefan Mengel","orcid":null},"institutions":[{"id":"https://openalex.org/I206945453","display_name":"Paderborn University","ror":"https://ror.org/058kzsd48","country_code":"DE","type":"education","lineage":["https://openalex.org/I206945453"]}],"countries":["DE"],"is_corresponding":false,"raw_author_name":"Stefan Mengel","raw_affiliation_strings":["University of Paderborn, Paderborn, Germany","University of Paderborn,, Paderborn, Germany"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"University of Paderborn, Paderborn, Germany","institution_ids":["https://openalex.org/I206945453"]},{"raw_affiliation_string":"University of Paderborn,, Paderborn, Germany","institution_ids":["https://openalex.org/I206945453"]}]}],"institutions":[],"countries_distinct_count":2,"institutions_distinct_count":3,"corresponding_author_ids":[],"corresponding_institution_ids":[],"apc_list":null,"apc_paid":null,"fwci":null,"has_fulltext":false,"cited_by_count":11,"citation_normalized_percentile":null,"cited_by_percentile_year":null,"biblio":{"volume":null,"issue":null,"first_page":"81","last_page":"92"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T10374","display_name":"Advanced Graph Theory Research","score":0.9997000098228455,"subfield":{"id":"https://openalex.org/subfields/1703","display_name":"Computational Theory and Mathematics"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},"topics":[{"id":"https://openalex.org/T10374","display_name":"Advanced Graph Theory Research","score":0.9997000098228455,"subfield":{"id":"https://openalex.org/subfields/1703","display_name":"Computational Theory and Mathematics"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T12056","display_name":"Markov Chains and Monte Carlo Methods","score":0.9976999759674072,"subfield":{"id":"https://openalex.org/subfields/2613","display_name":"Statistics and Probability"},"field":{"id":"https://openalex.org/fields/26","display_name":"Mathematics"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T11106","display_name":"Data Management and Algorithms","score":0.9972000122070312,"subfield":{"id":"https://openalex.org/subfields/1711","display_name":"Signal Processing"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/hyperbolic-tree","display_name":"Hyperbolic tree","score":0.9480438828468323},{"id":"https://openalex.org/keywords/treewidth","display_name":"Treewidth","score":0.8946771025657654},{"id":"https://openalex.org/keywords/conjunctive-query","display_name":"Conjunctive query","score":0.8139777183532715},{"id":"https://openalex.org/keywords/parameterized-complexity","display_name":"Parameterized complexity","score":0.7775305509567261},{"id":"https://openalex.org/keywords/bounded-function","display_name":"Bounded function","score":0.7478770017623901},{"id":"https://openalex.org/keywords/star","display_name":"Star (game theory)","score":0.5966695547103882},{"id":"https://openalex.org/keywords/arity","display_name":"Arity","score":0.5776765942573547},{"id":"https://openalex.org/keywords/mathematics","display_name":"Mathematics","score":0.5523170828819275},{"id":"https://openalex.org/keywords/tree-decomposition","display_name":"Tree decomposition","score":0.46423855423927307},{"id":"https://openalex.org/keywords/representation","display_name":"Representation (politics)","score":0.4270434081554413},{"id":"https://openalex.org/keywords/combinatorics","display_name":"Combinatorics","score":0.36720025539398193},{"id":"https://openalex.org/keywords/discrete-mathematics","display_name":"Discrete mathematics","score":0.36557477712631226},{"id":"https://openalex.org/keywords/computer-science","display_name":"Computer science","score":0.319837749004364},{"id":"https://openalex.org/keywords/graph","display_name":"Graph","score":0.1783657670021057},{"id":"https://openalex.org/keywords/pathwidth","display_name":"Pathwidth","score":0.11766427755355835},{"id":"https://openalex.org/keywords/pure-mathematics","display_name":"Pure mathematics","score":0.09180131554603577},{"id":"https://openalex.org/keywords/hyperbolic-geometry","display_name":"Hyperbolic geometry","score":0.0831078588962555}],"concepts":[{"id":"https://openalex.org/C97654310","wikidata":"https://www.wikidata.org/wiki/Q574023","display_name":"Hyperbolic tree","level":4,"score":0.9480438828468323},{"id":"https://openalex.org/C132569581","wikidata":"https://www.wikidata.org/wiki/Q5067368","display_name":"Treewidth","level":5,"score":0.8946771025657654},{"id":"https://openalex.org/C65647387","wikidata":"https://www.wikidata.org/wiki/Q1781706","display_name":"Conjunctive query","level":3,"score":0.8139777183532715},{"id":"https://openalex.org/C165464430","wikidata":"https://www.wikidata.org/wiki/Q1570441","display_name":"Parameterized complexity","level":2,"score":0.7775305509567261},{"id":"https://openalex.org/C34388435","wikidata":"https://www.wikidata.org/wiki/Q2267362","display_name":"Bounded function","level":2,"score":0.7478770017623901},{"id":"https://openalex.org/C2780897414","wikidata":"https://www.wikidata.org/wiki/Q7600592","display_name":"Star (game theory)","level":2,"score":0.5966695547103882},{"id":"https://openalex.org/C110546421","wikidata":"https://www.wikidata.org/wiki/Q1315869","display_name":"Arity","level":2,"score":0.5776765942573547},{"id":"https://openalex.org/C33923547","wikidata":"https://www.wikidata.org/wiki/Q395","display_name":"Mathematics","level":0,"score":0.5523170828819275},{"id":"https://openalex.org/C70501317","wikidata":"https://www.wikidata.org/wiki/Q462095","display_name":"Tree decomposition","level":5,"score":0.46423855423927307},{"id":"https://openalex.org/C2776359362","wikidata":"https://www.wikidata.org/wiki/Q2145286","display_name":"Representation (politics)","level":3,"score":0.4270434081554413},{"id":"https://openalex.org/C114614502","wikidata":"https://www.wikidata.org/wiki/Q76592","display_name":"Combinatorics","level":1,"score":0.36720025539398193},{"id":"https://openalex.org/C118615104","wikidata":"https://www.wikidata.org/wiki/Q121416","display_name":"Discrete mathematics","level":1,"score":0.36557477712631226},{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.319837749004364},{"id":"https://openalex.org/C132525143","wikidata":"https://www.wikidata.org/wiki/Q141488","display_name":"Graph","level":2,"score":0.1783657670021057},{"id":"https://openalex.org/C43517604","wikidata":"https://www.wikidata.org/wiki/Q7144893","display_name":"Pathwidth","level":4,"score":0.11766427755355835},{"id":"https://openalex.org/C202444582","wikidata":"https://www.wikidata.org/wiki/Q837863","display_name":"Pure mathematics","level":1,"score":0.09180131554603577},{"id":"https://openalex.org/C206352148","wikidata":"https://www.wikidata.org/wiki/Q209306","display_name":"Hyperbolic geometry","level":3,"score":0.0831078588962555},{"id":"https://openalex.org/C192939610","wikidata":"https://www.wikidata.org/wiki/Q188444","display_name":"Differential geometry","level":2,"score":0.0},{"id":"https://openalex.org/C17744445","wikidata":"https://www.wikidata.org/wiki/Q36442","display_name":"Political science","level":0,"score":0.0},{"id":"https://openalex.org/C77088390","wikidata":"https://www.wikidata.org/wiki/Q8513","display_name":"Database","level":1,"score":0.0},{"id":"https://openalex.org/C199539241","wikidata":"https://www.wikidata.org/wiki/Q7748","display_name":"Law","level":1,"score":0.0},{"id":"https://openalex.org/C134306372","wikidata":"https://www.wikidata.org/wiki/Q7754","display_name":"Mathematical analysis","level":1,"score":0.0},{"id":"https://openalex.org/C203776342","wikidata":"https://www.wikidata.org/wiki/Q1378376","display_name":"Line graph","level":3,"score":0.0},{"id":"https://openalex.org/C5655090","wikidata":"https://www.wikidata.org/wiki/Q192588","display_name":"Relational database","level":2,"score":0.0},{"id":"https://openalex.org/C94625758","wikidata":"https://www.wikidata.org/wiki/Q7163","display_name":"Politics","level":2,"score":0.0}],"mesh":[],"locations_count":1,"locations":[{"id":"doi:10.1145/2448496.2448508","is_oa":false,"landing_page_url":"https://doi.org/10.1145/2448496.2448508","pdf_url":null,"source":null,"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Proceedings of the 16th International Conference on Database Theory","raw_type":"proceedings-article"}],"best_oa_location":null,"sustainable_development_goals":[],"awards":[{"id":"https://openalex.org/G5696035834","display_name":null,"funder_award_id":"BU 1371/2-2, BU 1371/3-1","funder_id":"https://openalex.org/F4320320879","funder_display_name":"Deutsche Forschungsgemeinschaft"},{"id":"https://openalex.org/G5903195309","display_name":null,"funder_award_id":"238381","funder_id":"https://openalex.org/F4320334960","funder_display_name":"Seventh Framework Programme"}],"funders":[{"id":"https://openalex.org/F4320320879","display_name":"Deutsche Forschungsgemeinschaft","ror":"https://ror.org/018mejw64"},{"id":"https://openalex.org/F4320320883","display_name":"Agence Nationale de la Recherche","ror":"https://ror.org/00rbzpz17"},{"id":"https://openalex.org/F4320334960","display_name":"Seventh Framework Programme","ror":"https://ror.org/00k4n6c32"}],"has_content":{"grobid_xml":false,"pdf":false},"content_urls":null,"referenced_works_count":39,"referenced_works":["https://openalex.org/W36639738","https://openalex.org/W51516856","https://openalex.org/W52840101","https://openalex.org/W1489366126","https://openalex.org/W1527664624","https://openalex.org/W1558832481","https://openalex.org/W1570425181","https://openalex.org/W1579803282","https://openalex.org/W1787617900","https://openalex.org/W1978282744","https://openalex.org/W1983022219","https://openalex.org/W1998342956","https://openalex.org/W2008536061","https://openalex.org/W2024291212","https://openalex.org/W2026745535","https://openalex.org/W2027519504","https://openalex.org/W2029448190","https://openalex.org/W2033325972","https://openalex.org/W2034674470","https://openalex.org/W2036350338","https://openalex.org/W2046652577","https://openalex.org/W2049559029","https://openalex.org/W2057256946","https://openalex.org/W2059372025","https://openalex.org/W2065023965","https://openalex.org/W2077814962","https://openalex.org/W2087083200","https://openalex.org/W2111829945","https://openalex.org/W2118076394","https://openalex.org/W2153629319","https://openalex.org/W2404143746","https://openalex.org/W2490706771","https://openalex.org/W2605194663","https://openalex.org/W2798588639","https://openalex.org/W2913688336","https://openalex.org/W2914039150","https://openalex.org/W6602175484","https://openalex.org/W6633989784","https://openalex.org/W6677874516"],"related_works":["https://openalex.org/W2480025839","https://openalex.org/W2134402143","https://openalex.org/W2950294966","https://openalex.org/W4292713356","https://openalex.org/W2628596753","https://openalex.org/W1988026822","https://openalex.org/W2032444001","https://openalex.org/W2401514316","https://openalex.org/W3169968423","https://openalex.org/W2533772561"],"abstract_inverted_index":{"In":[0],"this":[1],"paper":[2],"we":[3,106],"explore":[4],"the":[5,18,29,63,70,83,89,94,101,111,177,182,185],"problem":[6],"of":[7,22,50,65,72,96,103,115,125,169,184],"counting":[8,69,88],"solutions":[9,73,90],"to":[10,80,156,165],"conjunctive":[11,40,84],"queries.":[12],"We":[13,36,161],"consider":[14],"a":[15,23,116],"parameter":[16,137,159],"called":[17],"quantified":[19,58,112,131,170],"star":[20,59,113,132,171],"size":[21,60,114,133,172],"formula":[24,117],"\u03c6":[25],"which":[26,68,87],"measures":[27],"how":[28,164],"free":[30],"variables":[31],"are":[32],"spread":[33],"in":[34,93,120,173],"\u03c6.":[35],"show":[37,108,163],"that":[38,42,109],"for":[39,67,86,123,149],"queries":[41,66,85,124],"admit":[43],"nice":[44],"decomposition":[45],"properties":[46],"(such":[47],"as":[48],"being":[49],"bounded":[51,57,97],"treewidth":[52],"or":[53],"generalized":[54,126,150],"hypertree":[55,127,151],"width)":[56],"exactly":[61],"characterizes":[62],"classes":[64],"number":[71],"is":[74,91,118,134,147],"tractable.":[75,160],"This":[76],"also":[77,107],"allows":[78],"us":[79],"fully":[81],"characterize":[82],"tractable":[92,138],"case":[95],"arity.":[98],"To":[99],"illustrate":[100],"applicability":[102],"our":[104],"results,":[105],"computing":[110],"possible":[119],"time":[121,175],"nO(k)":[122],"width":[128,143,152,183],"k.":[129],"Furthermore,":[130],"even":[135],"fixed":[136,158],"parameterized":[139],"by":[140],"some":[141],"other":[142],"measures,":[144],"while":[145],"it":[146],"W[1]-hard":[148],"and":[153],"thus":[154],"unlikely":[155],"be":[157],"finally":[162],"compute":[166],"an":[167],"approximation":[168,178],"polynomial":[174],"where":[176],"ratio":[179],"depends":[180],"on":[181],"input.":[186]},"counts_by_year":[{"year":2025,"cited_by_count":1},{"year":2024,"cited_by_count":1},{"year":2018,"cited_by_count":1},{"year":2017,"cited_by_count":3},{"year":2016,"cited_by_count":1},{"year":2015,"cited_by_count":2},{"year":2014,"cited_by_count":2}],"updated_date":"2026-07-14T23:27:15.235271","created_date":"2025-10-10T00:00:00"}