{"id":"https://openalex.org/W2063645305","doi":"https://doi.org/10.1016/0022-0000(78)90009-0","title":"Candidate keys for relations","display_name":"Candidate keys for relations","publication_year":1978,"publication_date":"1978-10-01","ids":{"openalex":"https://openalex.org/W2063645305","doi":"https://doi.org/10.1016/0022-0000(78)90009-0","mag":"2063645305"},"language":"en","primary_location":{"id":"doi:10.1016/0022-0000(78)90009-0","is_oa":false,"landing_page_url":"https://doi.org/10.1016/0022-0000(78)90009-0","pdf_url":null,"source":{"id":"https://openalex.org/S141020589","display_name":"Journal of Computer and System Sciences","issn_l":"0022-0000","issn":["0022-0000","1090-2724"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310320990","host_organization_name":"Elsevier BV","host_organization_lineage":["https://openalex.org/P4310320990"],"host_organization_lineage_names":["Elsevier BV"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Journal of Computer and System Sciences","raw_type":"journal-article"},"type":"article","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/A5064031252","display_name":"Cl\u00e1udio L. Lucchesi","orcid":null},"institutions":[{"id":"https://openalex.org/I181391015","display_name":"Universidade Estadual de Campinas (UNICAMP)","ror":"https://ror.org/04wffgt70","country_code":"BR","type":"education","lineage":["https://openalex.org/I181391015"]}],"countries":["BR"],"is_corresponding":false,"raw_author_name":"Cl\u00e1udio L. Lucchesi","raw_affiliation_strings":["Universidade Estadual de Campinas, 13100 Campinas, sp, Brazil"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Universidade Estadual de Campinas, 13100 Campinas, sp, Brazil","institution_ids":["https://openalex.org/I181391015"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5039210227","display_name":"Sylvia L. Osborn","orcid":null},"institutions":[{"id":"https://openalex.org/I151746483","display_name":"University of Waterloo","ror":"https://ror.org/01aff2v68","country_code":"CA","type":"education","lineage":["https://openalex.org/I151746483"]}],"countries":["CA"],"is_corresponding":false,"raw_author_name":"Sylvia L. Osborn","raw_affiliation_strings":["University of Waterloo, Waterloo, Ontario, Canada, 3G1"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"University of Waterloo, Waterloo, Ontario, Canada, 3G1","institution_ids":["https://openalex.org/I151746483"]}]}],"institutions":[],"countries_distinct_count":2,"institutions_distinct_count":2,"corresponding_author_ids":[],"corresponding_institution_ids":[],"apc_list":{"value":2520,"currency":"USD","value_usd":2520},"apc_paid":null,"fwci":4.2773,"has_fulltext":false,"cited_by_count":154,"citation_normalized_percentile":{"value":0.94017333,"is_in_top_1_percent":false,"is_in_top_10_percent":true},"cited_by_percentile_year":{"min":94,"max":99},"biblio":{"volume":"17","issue":"2","first_page":"270","last_page":"279"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T10317","display_name":"Advanced Database Systems and Queries","score":0.9993000030517578,"subfield":{"id":"https://openalex.org/subfields/1705","display_name":"Computer Networks and Communications"},"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/T10317","display_name":"Advanced Database Systems and Queries","score":0.9993000030517578,"subfield":{"id":"https://openalex.org/subfields/1705","display_name":"Computer Networks and Communications"},"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/T11106","display_name":"Data Management and Algorithms","score":0.9984999895095825,"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"}},{"id":"https://openalex.org/T11727","display_name":"Advanced Algebra and Logic","score":0.9675999879837036,"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"}}],"keywords":[{"id":"https://openalex.org/keywords/cardinality","display_name":"Cardinality (data modeling)","score":0.8121060132980347},{"id":"https://openalex.org/keywords/set","display_name":"Set (abstract data type)","score":0.6447073221206665},{"id":"https://openalex.org/keywords/mathematics","display_name":"Mathematics","score":0.5677809715270996},{"id":"https://openalex.org/keywords/prime","display_name":"Prime (order theory)","score":0.5337551236152649},{"id":"https://openalex.org/keywords/discrete-mathematics","display_name":"Discrete mathematics","score":0.529925525188446},{"id":"https://openalex.org/keywords/combinatorics","display_name":"Combinatorics","score":0.5295724868774414},{"id":"https://openalex.org/keywords/integer","display_name":"Integer (computer science)","score":0.5034648776054382},{"id":"https://openalex.org/keywords/time-complexity","display_name":"Time complexity","score":0.485504150390625},{"id":"https://openalex.org/keywords/key","display_name":"Key (lock)","score":0.48500677943229675},{"id":"https://openalex.org/keywords/computer-science","display_name":"Computer science","score":0.4236254394054413},{"id":"https://openalex.org/keywords/np-complete","display_name":"NP-complete","score":0.4166281223297119},{"id":"https://openalex.org/keywords/data-mining","display_name":"Data mining","score":0.07161960005760193},{"id":"https://openalex.org/keywords/computer-security","display_name":"Computer security","score":0.059660106897354126}],"concepts":[{"id":"https://openalex.org/C87117476","wikidata":"https://www.wikidata.org/wiki/Q362383","display_name":"Cardinality (data modeling)","level":2,"score":0.8121060132980347},{"id":"https://openalex.org/C177264268","wikidata":"https://www.wikidata.org/wiki/Q1514741","display_name":"Set (abstract data type)","level":2,"score":0.6447073221206665},{"id":"https://openalex.org/C33923547","wikidata":"https://www.wikidata.org/wiki/Q395","display_name":"Mathematics","level":0,"score":0.5677809715270996},{"id":"https://openalex.org/C184992742","wikidata":"https://www.wikidata.org/wiki/Q7243229","display_name":"Prime (order theory)","level":2,"score":0.5337551236152649},{"id":"https://openalex.org/C118615104","wikidata":"https://www.wikidata.org/wiki/Q121416","display_name":"Discrete mathematics","level":1,"score":0.529925525188446},{"id":"https://openalex.org/C114614502","wikidata":"https://www.wikidata.org/wiki/Q76592","display_name":"Combinatorics","level":1,"score":0.5295724868774414},{"id":"https://openalex.org/C97137487","wikidata":"https://www.wikidata.org/wiki/Q729138","display_name":"Integer (computer science)","level":2,"score":0.5034648776054382},{"id":"https://openalex.org/C311688","wikidata":"https://www.wikidata.org/wiki/Q2393193","display_name":"Time complexity","level":2,"score":0.485504150390625},{"id":"https://openalex.org/C26517878","wikidata":"https://www.wikidata.org/wiki/Q228039","display_name":"Key (lock)","level":2,"score":0.48500677943229675},{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.4236254394054413},{"id":"https://openalex.org/C122749075","wikidata":"https://www.wikidata.org/wiki/Q215206","display_name":"NP-complete","level":3,"score":0.4166281223297119},{"id":"https://openalex.org/C124101348","wikidata":"https://www.wikidata.org/wiki/Q172491","display_name":"Data mining","level":1,"score":0.07161960005760193},{"id":"https://openalex.org/C38652104","wikidata":"https://www.wikidata.org/wiki/Q3510521","display_name":"Computer security","level":1,"score":0.059660106897354126},{"id":"https://openalex.org/C199360897","wikidata":"https://www.wikidata.org/wiki/Q9143","display_name":"Programming language","level":1,"score":0.0}],"mesh":[],"locations_count":1,"locations":[{"id":"doi:10.1016/0022-0000(78)90009-0","is_oa":false,"landing_page_url":"https://doi.org/10.1016/0022-0000(78)90009-0","pdf_url":null,"source":{"id":"https://openalex.org/S141020589","display_name":"Journal of Computer and System Sciences","issn_l":"0022-0000","issn":["0022-0000","1090-2724"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310320990","host_organization_name":"Elsevier BV","host_organization_lineage":["https://openalex.org/P4310320990"],"host_organization_lineage_names":["Elsevier BV"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Journal of Computer and System Sciences","raw_type":"journal-article"}],"best_oa_location":null,"sustainable_development_goals":[],"awards":[],"funders":[],"has_content":{"pdf":false,"grobid_xml":false},"content_urls":null,"referenced_works_count":19,"referenced_works":["https://openalex.org/W57410335","https://openalex.org/W1504925519","https://openalex.org/W1513575755","https://openalex.org/W2036265926","https://openalex.org/W2048841336","https://openalex.org/W2066356146","https://openalex.org/W2074023317","https://openalex.org/W2078236992","https://openalex.org/W2165467455","https://openalex.org/W2185907055","https://openalex.org/W2232207765","https://openalex.org/W2401610261","https://openalex.org/W6602347050","https://openalex.org/W6630672200","https://openalex.org/W6644040475","https://openalex.org/W6659573362","https://openalex.org/W6662690152","https://openalex.org/W6670142289","https://openalex.org/W6689392195"],"related_works":["https://openalex.org/W2080188430","https://openalex.org/W2151692582","https://openalex.org/W2024680387","https://openalex.org/W2132038253","https://openalex.org/W3173107589","https://openalex.org/W3129621902","https://openalex.org/W2793745936","https://openalex.org/W3098671307","https://openalex.org/W2044816189","https://openalex.org/W2502624504"],"abstract_inverted_index":null,"counts_by_year":[{"year":2026,"cited_by_count":3},{"year":2025,"cited_by_count":2},{"year":2024,"cited_by_count":3},{"year":2023,"cited_by_count":4},{"year":2022,"cited_by_count":4},{"year":2021,"cited_by_count":5},{"year":2020,"cited_by_count":2},{"year":2019,"cited_by_count":6},{"year":2018,"cited_by_count":5},{"year":2017,"cited_by_count":2},{"year":2016,"cited_by_count":12},{"year":2015,"cited_by_count":3},{"year":2014,"cited_by_count":6},{"year":2013,"cited_by_count":3},{"year":2012,"cited_by_count":6}],"updated_date":"2026-06-11T09:08:48.828518","created_date":"2025-10-10T00:00:00"}
