{"id":"https://openalex.org/W1547830959","doi":"https://doi.org/10.1007/3-540-09541-1_27","title":"Equivalent key problem of the relational database model","display_name":"Equivalent key problem of the relational database model","publication_year":1979,"publication_date":"1979-01-01","ids":{"openalex":"https://openalex.org/W1547830959","doi":"https://doi.org/10.1007/3-540-09541-1_27","mag":"1547830959"},"language":"en","primary_location":{"id":"doi:10.1007/3-540-09541-1_27","is_oa":false,"landing_page_url":"https://doi.org/10.1007/3-540-09541-1_27","pdf_url":null,"source":{"id":"https://openalex.org/S106296714","display_name":"Lecture notes in computer science","issn_l":"0302-9743","issn":["0302-9743","1611-3349"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310319900","host_organization_name":"Springer Science+Business Media","host_organization_lineage":["https://openalex.org/P4310319900","https://openalex.org/P4310319965"],"host_organization_lineage_names":["Springer Science+Business Media","Springer Nature"],"type":"book series"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Lecture Notes in Computer Science","raw_type":"book-chapter"},"type":"book-chapter","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/A5103702858","display_name":"Yahiko Kambayashi","orcid":null},"institutions":[{"id":"https://openalex.org/I22299242","display_name":"Kyoto University","ror":"https://ror.org/02kpeqv85","country_code":"JP","type":"education","lineage":["https://openalex.org/I22299242"]}],"countries":["JP"],"is_corresponding":true,"raw_author_name":"Yahiko Kambayashi","raw_affiliation_strings":["Department of Information Science, Kyoto University, 606, Sakyo, Kyoto, Japan","Department of Information Science, Kyoto University, Sakyo, Kyoto, Japan"],"affiliations":[{"raw_affiliation_string":"Department of Information Science, Kyoto University, 606, Sakyo, Kyoto, Japan","institution_ids":["https://openalex.org/I22299242"]},{"raw_affiliation_string":"Department of Information Science, Kyoto University, Sakyo, Kyoto, Japan","institution_ids":["https://openalex.org/I22299242"]}]}],"institutions":[],"countries_distinct_count":1,"institutions_distinct_count":1,"corresponding_author_ids":["https://openalex.org/A5103702858"],"corresponding_institution_ids":["https://openalex.org/I22299242"],"apc_list":{"value":5000,"currency":"EUR","value_usd":5392},"apc_paid":null,"fwci":6.3609,"has_fulltext":false,"cited_by_count":4,"citation_normalized_percentile":{"value":0.96797153,"is_in_top_1_percent":false,"is_in_top_10_percent":true},"cited_by_percentile_year":{"min":89,"max":93},"biblio":{"volume":null,"issue":null,"first_page":"165","last_page":"192"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T10317","display_name":"Advanced Database Systems and Queries","score":0.9998000264167786,"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":0.9998000264167786,"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":0.9993000030517578,"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/T10215","display_name":"Semantic Web and Ontologies","score":0.9854000210762024,"subfield":{"id":"https://openalex.org/subfields/1702","display_name":"Artificial Intelligence"},"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/equivalence-relation","display_name":"Equivalence relation","score":0.7168384790420532},{"id":"https://openalex.org/keywords/relational-database","display_name":"Relational database","score":0.5876179933547974},{"id":"https://openalex.org/keywords/equivalence","display_name":"Equivalence (formal languages)","score":0.5634410381317139},{"id":"https://openalex.org/keywords/key","display_name":"Key (lock)","score":0.551308810710907},{"id":"https://openalex.org/keywords/schema","display_name":"Schema (genetic algorithms)","score":0.5399678945541382},{"id":"https://openalex.org/keywords/relational-model","display_name":"Relational model","score":0.526541531085968},{"id":"https://openalex.org/keywords/computer-science","display_name":"Computer science","score":0.4888452887535095},{"id":"https://openalex.org/keywords/logical-equivalence","display_name":"Logical equivalence","score":0.4760841429233551},{"id":"https://openalex.org/keywords/normalization","display_name":"Normalization (sociology)","score":0.45803123712539673},{"id":"https://openalex.org/keywords/minification","display_name":"Minification","score":0.4524366855621338},{"id":"https://openalex.org/keywords/mathematics","display_name":"Mathematics","score":0.4065421223640442},{"id":"https://openalex.org/keywords/algorithm","display_name":"Algorithm","score":0.4065108299255371},{"id":"https://openalex.org/keywords/theoretical-computer-science","display_name":"Theoretical computer science","score":0.4031863212585449},{"id":"https://openalex.org/keywords/mathematical-optimization","display_name":"Mathematical optimization","score":0.19151955842971802},{"id":"https://openalex.org/keywords/discrete-mathematics","display_name":"Discrete mathematics","score":0.19135361909866333},{"id":"https://openalex.org/keywords/data-mining","display_name":"Data mining","score":0.17733162641525269},{"id":"https://openalex.org/keywords/information-retrieval","display_name":"Information retrieval","score":0.09370002150535583}],"concepts":[{"id":"https://openalex.org/C156103551","wikidata":"https://www.wikidata.org/wiki/Q130998","display_name":"Equivalence relation","level":2,"score":0.7168384790420532},{"id":"https://openalex.org/C5655090","wikidata":"https://www.wikidata.org/wiki/Q192588","display_name":"Relational database","level":2,"score":0.5876179933547974},{"id":"https://openalex.org/C2780069185","wikidata":"https://www.wikidata.org/wiki/Q7977945","display_name":"Equivalence (formal languages)","level":2,"score":0.5634410381317139},{"id":"https://openalex.org/C26517878","wikidata":"https://www.wikidata.org/wiki/Q228039","display_name":"Key (lock)","level":2,"score":0.551308810710907},{"id":"https://openalex.org/C52146309","wikidata":"https://www.wikidata.org/wiki/Q7431116","display_name":"Schema (genetic algorithms)","level":2,"score":0.5399678945541382},{"id":"https://openalex.org/C40207289","wikidata":"https://www.wikidata.org/wiki/Q755662","display_name":"Relational model","level":3,"score":0.526541531085968},{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.4888452887535095},{"id":"https://openalex.org/C70846408","wikidata":"https://www.wikidata.org/wiki/Q220433","display_name":"Logical equivalence","level":3,"score":0.4760841429233551},{"id":"https://openalex.org/C136886441","wikidata":"https://www.wikidata.org/wiki/Q926129","display_name":"Normalization (sociology)","level":2,"score":0.45803123712539673},{"id":"https://openalex.org/C147764199","wikidata":"https://www.wikidata.org/wiki/Q6865248","display_name":"Minification","level":2,"score":0.4524366855621338},{"id":"https://openalex.org/C33923547","wikidata":"https://www.wikidata.org/wiki/Q395","display_name":"Mathematics","level":0,"score":0.4065421223640442},{"id":"https://openalex.org/C11413529","wikidata":"https://www.wikidata.org/wiki/Q8366","display_name":"Algorithm","level":1,"score":0.4065108299255371},{"id":"https://openalex.org/C80444323","wikidata":"https://www.wikidata.org/wiki/Q2878974","display_name":"Theoretical computer science","level":1,"score":0.4031863212585449},{"id":"https://openalex.org/C126255220","wikidata":"https://www.wikidata.org/wiki/Q141495","display_name":"Mathematical optimization","level":1,"score":0.19151955842971802},{"id":"https://openalex.org/C118615104","wikidata":"https://www.wikidata.org/wiki/Q121416","display_name":"Discrete mathematics","level":1,"score":0.19135361909866333},{"id":"https://openalex.org/C124101348","wikidata":"https://www.wikidata.org/wiki/Q172491","display_name":"Data mining","level":1,"score":0.17733162641525269},{"id":"https://openalex.org/C23123220","wikidata":"https://www.wikidata.org/wiki/Q816826","display_name":"Information retrieval","level":1,"score":0.09370002150535583},{"id":"https://openalex.org/C38652104","wikidata":"https://www.wikidata.org/wiki/Q3510521","display_name":"Computer security","level":1,"score":0.0},{"id":"https://openalex.org/C144024400","wikidata":"https://www.wikidata.org/wiki/Q21201","display_name":"Sociology","level":0,"score":0.0},{"id":"https://openalex.org/C19165224","wikidata":"https://www.wikidata.org/wiki/Q23404","display_name":"Anthropology","level":1,"score":0.0}],"mesh":[],"locations_count":1,"locations":[{"id":"doi:10.1007/3-540-09541-1_27","is_oa":false,"landing_page_url":"https://doi.org/10.1007/3-540-09541-1_27","pdf_url":null,"source":{"id":"https://openalex.org/S106296714","display_name":"Lecture notes in computer science","issn_l":"0302-9743","issn":["0302-9743","1611-3349"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310319900","host_organization_name":"Springer Science+Business Media","host_organization_lineage":["https://openalex.org/P4310319900","https://openalex.org/P4310319965"],"host_organization_lineage_names":["Springer Science+Business Media","Springer Nature"],"type":"book series"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Lecture Notes in Computer Science","raw_type":"book-chapter"}],"best_oa_location":null,"sustainable_development_goals":[],"awards":[],"funders":[],"has_content":{"grobid_xml":false,"pdf":false},"content_urls":null,"referenced_works_count":16,"referenced_works":["https://openalex.org/W43035074","https://openalex.org/W182312985","https://openalex.org/W196062972","https://openalex.org/W1547830959","https://openalex.org/W1609370892","https://openalex.org/W1975528398","https://openalex.org/W2023663289","https://openalex.org/W2024200923","https://openalex.org/W2074023317","https://openalex.org/W2110810394","https://openalex.org/W2132490332","https://openalex.org/W2165467455","https://openalex.org/W2185907055","https://openalex.org/W2204059200","https://openalex.org/W2232207765","https://openalex.org/W3023595663"],"related_works":["https://openalex.org/W2267077731","https://openalex.org/W1510134535","https://openalex.org/W2386578196","https://openalex.org/W2483382562","https://openalex.org/W3091612633","https://openalex.org/W2085988990","https://openalex.org/W1528519853","https://openalex.org/W2376710457","https://openalex.org/W1897774768","https://openalex.org/W3006903421"],"abstract_inverted_index":null,"counts_by_year":[{"year":2021,"cited_by_count":1}],"updated_date":"2025-11-06T03:46:38.306776","created_date":"2025-10-10T00:00:00"}