{"id":"https://openalex.org/W2008185459","doi":"https://doi.org/10.1016/0306-4379(92)90029-m","title":"On the complexity of finding bounds for projection cardinalities in relational databases","display_name":"On the complexity of finding bounds for projection cardinalities in relational databases","publication_year":1992,"publication_date":"1992-11-01","ids":{"openalex":"https://openalex.org/W2008185459","doi":"https://doi.org/10.1016/0306-4379(92)90029-m","mag":"2008185459"},"language":"en","primary_location":{"id":"doi:10.1016/0306-4379(92)90029-m","is_oa":false,"landing_page_url":"https://doi.org/10.1016/0306-4379(92)90029-m","pdf_url":null,"source":{"id":"https://openalex.org/S193006928","display_name":"Information Systems","issn_l":"0306-4379","issn":["0306-4379","1873-6076"],"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":"Information Systems","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/A5010984921","display_name":"Paolo Ciaccia","orcid":"https://orcid.org/0000-0002-1794-6244"},"institutions":[{"id":"https://openalex.org/I9360294","display_name":"University of Bologna","ror":"https://ror.org/01111rn36","country_code":"IT","type":"education","lineage":["https://openalex.org/I9360294"]}],"countries":["IT"],"is_corresponding":false,"raw_author_name":"Paolo Ciaccia","raw_affiliation_strings":["DEIS, Universit\u00e0 di Bologna, CIOC-C.N.R., Viale Risorgimento 2, 40136 Bologna, Italy"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"DEIS, Universit\u00e0 di Bologna, CIOC-C.N.R., Viale Risorgimento 2, 40136 Bologna, Italy","institution_ids":["https://openalex.org/I9360294"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5056262479","display_name":"Dario Maio","orcid":"https://orcid.org/0000-0002-0094-0022"},"institutions":[{"id":"https://openalex.org/I9360294","display_name":"University of Bologna","ror":"https://ror.org/01111rn36","country_code":"IT","type":"education","lineage":["https://openalex.org/I9360294"]}],"countries":["IT"],"is_corresponding":true,"raw_author_name":"Dario Maio","raw_affiliation_strings":["DEIS, Universit\u00e0 di Bologna, CIOC-C.N.R., Viale Risorgimento 2, 40136 Bologna, Italy"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"DEIS, Universit\u00e0 di Bologna, CIOC-C.N.R., Viale Risorgimento 2, 40136 Bologna, Italy","institution_ids":["https://openalex.org/I9360294"]}]}],"institutions":[],"countries_distinct_count":1,"institutions_distinct_count":1,"corresponding_author_ids":["https://openalex.org/A5056262479"],"corresponding_institution_ids":["https://openalex.org/I9360294"],"apc_list":{"value":3410,"currency":"USD","value_usd":3410},"apc_paid":null,"fwci":0.493,"has_fulltext":false,"cited_by_count":4,"citation_normalized_percentile":{"value":0.69689931,"is_in_top_1_percent":false,"is_in_top_10_percent":false},"cited_by_percentile_year":{"min":89,"max":94},"biblio":{"volume":"17","issue":"6","first_page":"511","last_page":"515"},"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/T10215","display_name":"Semantic Web and Ontologies","score":0.9987999796867371,"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"}},{"id":"https://openalex.org/T11106","display_name":"Data Management and Algorithms","score":0.9977999925613403,"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/cardinality","display_name":"Cardinality (data modeling)","score":0.8115545511245728},{"id":"https://openalex.org/keywords/upper-and-lower-bounds","display_name":"Upper and lower bounds","score":0.7435787916183472},{"id":"https://openalex.org/keywords/schema","display_name":"Schema (genetic algorithms)","score":0.6831666827201843},{"id":"https://openalex.org/keywords/relational-database","display_name":"Relational database","score":0.6567337512969971},{"id":"https://openalex.org/keywords/computer-science","display_name":"Computer science","score":0.5674081444740295},{"id":"https://openalex.org/keywords/conjunctive-query","display_name":"Conjunctive query","score":0.5364454984664917},{"id":"https://openalex.org/keywords/projection","display_name":"Projection (relational algebra)","score":0.46704381704330444},{"id":"https://openalex.org/keywords/set","display_name":"Set (abstract data type)","score":0.4246603548526764},{"id":"https://openalex.org/keywords/mathematics","display_name":"Mathematics","score":0.42282533645629883},{"id":"https://openalex.org/keywords/combinatorics","display_name":"Combinatorics","score":0.40667280554771423},{"id":"https://openalex.org/keywords/algorithm","display_name":"Algorithm","score":0.31656259298324585},{"id":"https://openalex.org/keywords/database","display_name":"Database","score":0.2984534502029419},{"id":"https://openalex.org/keywords/information-retrieval","display_name":"Information retrieval","score":0.10384759306907654}],"concepts":[{"id":"https://openalex.org/C87117476","wikidata":"https://www.wikidata.org/wiki/Q362383","display_name":"Cardinality (data modeling)","level":2,"score":0.8115545511245728},{"id":"https://openalex.org/C77553402","wikidata":"https://www.wikidata.org/wiki/Q13222579","display_name":"Upper and lower bounds","level":2,"score":0.7435787916183472},{"id":"https://openalex.org/C52146309","wikidata":"https://www.wikidata.org/wiki/Q7431116","display_name":"Schema (genetic algorithms)","level":2,"score":0.6831666827201843},{"id":"https://openalex.org/C5655090","wikidata":"https://www.wikidata.org/wiki/Q192588","display_name":"Relational database","level":2,"score":0.6567337512969971},{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.5674081444740295},{"id":"https://openalex.org/C65647387","wikidata":"https://www.wikidata.org/wiki/Q1781706","display_name":"Conjunctive query","level":3,"score":0.5364454984664917},{"id":"https://openalex.org/C57493831","wikidata":"https://www.wikidata.org/wiki/Q3134666","display_name":"Projection (relational algebra)","level":2,"score":0.46704381704330444},{"id":"https://openalex.org/C177264268","wikidata":"https://www.wikidata.org/wiki/Q1514741","display_name":"Set (abstract data type)","level":2,"score":0.4246603548526764},{"id":"https://openalex.org/C33923547","wikidata":"https://www.wikidata.org/wiki/Q395","display_name":"Mathematics","level":0,"score":0.42282533645629883},{"id":"https://openalex.org/C114614502","wikidata":"https://www.wikidata.org/wiki/Q76592","display_name":"Combinatorics","level":1,"score":0.40667280554771423},{"id":"https://openalex.org/C11413529","wikidata":"https://www.wikidata.org/wiki/Q8366","display_name":"Algorithm","level":1,"score":0.31656259298324585},{"id":"https://openalex.org/C77088390","wikidata":"https://www.wikidata.org/wiki/Q8513","display_name":"Database","level":1,"score":0.2984534502029419},{"id":"https://openalex.org/C23123220","wikidata":"https://www.wikidata.org/wiki/Q816826","display_name":"Information retrieval","level":1,"score":0.10384759306907654},{"id":"https://openalex.org/C199360897","wikidata":"https://www.wikidata.org/wiki/Q9143","display_name":"Programming language","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}],"mesh":[],"locations_count":2,"locations":[{"id":"doi:10.1016/0306-4379(92)90029-m","is_oa":false,"landing_page_url":"https://doi.org/10.1016/0306-4379(92)90029-m","pdf_url":null,"source":{"id":"https://openalex.org/S193006928","display_name":"Information Systems","issn_l":"0306-4379","issn":["0306-4379","1873-6076"],"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":"Information Systems","raw_type":"journal-article"},{"id":"pmh:oai:cris.unibo.it:11585/918302","is_oa":false,"landing_page_url":"https://hdl.handle.net/11585/918302","pdf_url":null,"source":{"id":"https://openalex.org/S4306402579","display_name":"Archivio istituzionale della ricerca (Alma Mater Studiorum Universit\u00e0 di Bologna)","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"host_organization":"https://openalex.org/I4210117483","host_organization_name":"Istituto di Ematologia di Bologna","host_organization_lineage":["https://openalex.org/I4210117483"],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":null,"raw_type":"info:eu-repo/semantics/article"}],"best_oa_location":null,"sustainable_development_goals":[{"display_name":"Reduced inequalities","score":0.4699999988079071,"id":"https://metadata.un.org/sdg/10"}],"awards":[],"funders":[],"has_content":{"pdf":false,"grobid_xml":false},"content_urls":null,"referenced_works_count":6,"referenced_works":["https://openalex.org/W1991782662","https://openalex.org/W2042940152","https://openalex.org/W2046981631","https://openalex.org/W2048341095","https://openalex.org/W2063645305","https://openalex.org/W2135105491"],"related_works":["https://openalex.org/W2002177687","https://openalex.org/W2058438338","https://openalex.org/W3174970460","https://openalex.org/W2120436863","https://openalex.org/W4233495035","https://openalex.org/W1639806124","https://openalex.org/W206482712","https://openalex.org/W1494193231","https://openalex.org/W1979093255","https://openalex.org/W2288512712"],"abstract_inverted_index":null,"counts_by_year":[{"year":2015,"cited_by_count":1}],"updated_date":"2026-08-21T09:56:20.448147","created_date":"2016-06-24T00:00:00"}