{"id":"https://openalex.org/W2519931105","doi":"https://doi.org/10.1109/tkde.2016.2588490","title":"A Comprehensive Approach to \u2018Now\u2019 in Temporal Relational Databases: Semantics and Representation","display_name":"A Comprehensive Approach to \u2018Now\u2019 in Temporal Relational Databases: Semantics and Representation","publication_year":2016,"publication_date":"2016-07-07","ids":{"openalex":"https://openalex.org/W2519931105","doi":"https://doi.org/10.1109/tkde.2016.2588490","mag":"2519931105"},"language":"en","primary_location":{"id":"doi:10.1109/tkde.2016.2588490","is_oa":false,"landing_page_url":"https://doi.org/10.1109/tkde.2016.2588490","pdf_url":null,"source":{"id":"https://openalex.org/S30698027","display_name":"IEEE Transactions on Knowledge and Data Engineering","issn_l":"1041-4347","issn":["1041-4347","1558-2191","2326-3865"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310320439","host_organization_name":"IEEE Computer Society","host_organization_lineage":["https://openalex.org/P4310320439","https://openalex.org/P4310319808"],"host_organization_lineage_names":["IEEE Computer Society","Institute of Electrical and Electronics Engineers"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"IEEE Transactions on Knowledge and Data Engineering","raw_type":"journal-article"},"type":"article","indexed_in":["crossref"],"open_access":{"is_oa":true,"oa_status":"green","oa_url":"http://hdl.handle.net/2318/1634571","any_repository_has_fulltext":true},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5043355817","display_name":"Luca Anselma","orcid":"https://orcid.org/0000-0003-2292-6480"},"institutions":[{"id":"https://openalex.org/I55143463","display_name":"University of Turin","ror":"https://ror.org/048tbm396","country_code":"IT","type":"education","lineage":["https://openalex.org/I55143463"]}],"countries":["IT"],"is_corresponding":false,"raw_author_name":"Luca Anselma","raw_affiliation_strings":["Dipartimento di Informatica, Universit\u00e0 di Torino, Torino, Italy"],"raw_orcid":"https://orcid.org/0000-0003-2292-6480","affiliations":[{"raw_affiliation_string":"Dipartimento di Informatica, Universit\u00e0 di Torino, Torino, Italy","institution_ids":["https://openalex.org/I55143463"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5030137665","display_name":"Luca Piovesan","orcid":"https://orcid.org/0000-0002-5923-5061"},"institutions":[{"id":"https://openalex.org/I55143463","display_name":"University of Turin","ror":"https://ror.org/048tbm396","country_code":"IT","type":"education","lineage":["https://openalex.org/I55143463"]}],"countries":["IT"],"is_corresponding":false,"raw_author_name":"Luca Piovesan","raw_affiliation_strings":["Dipartimento di Informatica, Universit\u00e0 di Torino, Torino, Italy"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Dipartimento di Informatica, Universit\u00e0 di Torino, Torino, Italy","institution_ids":["https://openalex.org/I55143463"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5038675407","display_name":"Abdul Sattar","orcid":"https://orcid.org/0000-0002-2567-2052"},"institutions":[{"id":"https://openalex.org/I11701301","display_name":"Griffith University","ror":"https://ror.org/02sc3r913","country_code":"AU","type":"education","lineage":["https://openalex.org/I11701301"]}],"countries":["AU"],"is_corresponding":false,"raw_author_name":"Abdul Sattar","raw_affiliation_strings":["Institute for Integrated and Intelligent Systems, Nathan campus, Griffith University, Brisbane, Australia"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Institute for Integrated and Intelligent Systems, Nathan campus, Griffith University, Brisbane, Australia","institution_ids":["https://openalex.org/I11701301"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5043963873","display_name":"Bela Stanti\u0107","orcid":"https://orcid.org/0000-0003-0475-7951"},"institutions":[{"id":"https://openalex.org/I11701301","display_name":"Griffith University","ror":"https://ror.org/02sc3r913","country_code":"AU","type":"education","lineage":["https://openalex.org/I11701301"]}],"countries":["AU"],"is_corresponding":false,"raw_author_name":"Bela Stantic","raw_affiliation_strings":["Institute for Integrated and Intelligent Systems, Griffith University, Brisbane, Australia"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Institute for Integrated and Intelligent Systems, Griffith University, Brisbane, Australia","institution_ids":["https://openalex.org/I11701301"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5007745000","display_name":"Paolo Terenziani","orcid":"https://orcid.org/0000-0002-9014-7537"},"institutions":[{"id":"https://openalex.org/I123338534","display_name":"Universit\u00e0 degli Studi del Piemonte Orientale \u201cAmedeo Avogadro\u201d","ror":"https://ror.org/04387x656","country_code":"IT","type":"education","lineage":["https://openalex.org/I123338534"]}],"countries":["IT"],"is_corresponding":false,"raw_author_name":"Paolo Terenziani","raw_affiliation_strings":["Computer Science Institute, DISIT, Universit\u00e0 del Piemonte Orientale, Alessandria, Italy"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Computer Science Institute, DISIT, Universit\u00e0 del Piemonte Orientale, Alessandria, Italy","institution_ids":["https://openalex.org/I123338534"]}]}],"institutions":[],"countries_distinct_count":2,"institutions_distinct_count":3,"corresponding_author_ids":[],"corresponding_institution_ids":[],"apc_list":null,"apc_paid":null,"fwci":1.9831,"has_fulltext":true,"cited_by_count":15,"citation_normalized_percentile":{"value":0.8827456,"is_in_top_1_percent":false,"is_in_top_10_percent":false},"cited_by_percentile_year":{"min":90,"max":98},"biblio":{"volume":"28","issue":"10","first_page":"2538","last_page":"2551"},"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":0.9998000264167786,"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":0.9988999962806702,"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/computer-science","display_name":"Computer science","score":0.7451332807540894},{"id":"https://openalex.org/keywords/relational-algebra","display_name":"Relational algebra","score":0.6402554512023926},{"id":"https://openalex.org/keywords/relational-database","display_name":"Relational database","score":0.6395865678787231},{"id":"https://openalex.org/keywords/semantics","display_name":"Semantics (computer science)","score":0.5972567200660706},{"id":"https://openalex.org/keywords/relational-model","display_name":"Relational model","score":0.5758002400398254},{"id":"https://openalex.org/keywords/temporal-database","display_name":"Temporal database","score":0.5457723140716553},{"id":"https://openalex.org/keywords/database-model","display_name":"Database model","score":0.48164382576942444},{"id":"https://openalex.org/keywords/extension","display_name":"Extension (predicate logic)","score":0.4810193181037903},{"id":"https://openalex.org/keywords/correctness","display_name":"Correctness","score":0.4705743193626404},{"id":"https://openalex.org/keywords/data-model","display_name":"Data model (GIS)","score":0.4687903821468353},{"id":"https://openalex.org/keywords/database","display_name":"Database","score":0.46772515773773193},{"id":"https://openalex.org/keywords/relational-calculus","display_name":"Relational calculus","score":0.4353598952293396},{"id":"https://openalex.org/keywords/database-theory","display_name":"Database theory","score":0.42506444454193115},{"id":"https://openalex.org/keywords/representation","display_name":"Representation (politics)","score":0.41854673624038696},{"id":"https://openalex.org/keywords/relational-database-management-system","display_name":"Relational database management system","score":0.41646867990493774},{"id":"https://openalex.org/keywords/data-modeling","display_name":"Data modeling","score":0.4104936420917511},{"id":"https://openalex.org/keywords/theoretical-computer-science","display_name":"Theoretical computer science","score":0.39559197425842285},{"id":"https://openalex.org/keywords/information-retrieval","display_name":"Information retrieval","score":0.32993799448013306},{"id":"https://openalex.org/keywords/programming-language","display_name":"Programming language","score":0.24693375825881958},{"id":"https://openalex.org/keywords/artificial-intelligence","display_name":"Artificial intelligence","score":0.15108650922775269}],"concepts":[{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.7451332807540894},{"id":"https://openalex.org/C95916125","wikidata":"https://www.wikidata.org/wiki/Q840540","display_name":"Relational algebra","level":3,"score":0.6402554512023926},{"id":"https://openalex.org/C5655090","wikidata":"https://www.wikidata.org/wiki/Q192588","display_name":"Relational database","level":2,"score":0.6395865678787231},{"id":"https://openalex.org/C184337299","wikidata":"https://www.wikidata.org/wiki/Q1437428","display_name":"Semantics (computer science)","level":2,"score":0.5972567200660706},{"id":"https://openalex.org/C40207289","wikidata":"https://www.wikidata.org/wiki/Q755662","display_name":"Relational model","level":3,"score":0.5758002400398254},{"id":"https://openalex.org/C77277458","wikidata":"https://www.wikidata.org/wiki/Q1969246","display_name":"Temporal database","level":2,"score":0.5457723140716553},{"id":"https://openalex.org/C5968703","wikidata":"https://www.wikidata.org/wiki/Q267136","display_name":"Database model","level":3,"score":0.48164382576942444},{"id":"https://openalex.org/C2778029271","wikidata":"https://www.wikidata.org/wiki/Q5421931","display_name":"Extension (predicate logic)","level":2,"score":0.4810193181037903},{"id":"https://openalex.org/C55439883","wikidata":"https://www.wikidata.org/wiki/Q360812","display_name":"Correctness","level":2,"score":0.4705743193626404},{"id":"https://openalex.org/C100463513","wikidata":"https://www.wikidata.org/wiki/Q5227322","display_name":"Data model (GIS)","level":2,"score":0.4687903821468353},{"id":"https://openalex.org/C77088390","wikidata":"https://www.wikidata.org/wiki/Q8513","display_name":"Database","level":1,"score":0.46772515773773193},{"id":"https://openalex.org/C99436015","wikidata":"https://www.wikidata.org/wiki/Q1722436","display_name":"Relational calculus","level":4,"score":0.4353598952293396},{"id":"https://openalex.org/C12439846","wikidata":"https://www.wikidata.org/wiki/Q4809258","display_name":"Database theory","level":3,"score":0.42506444454193115},{"id":"https://openalex.org/C2776359362","wikidata":"https://www.wikidata.org/wiki/Q2145286","display_name":"Representation (politics)","level":3,"score":0.41854673624038696},{"id":"https://openalex.org/C24394798","wikidata":"https://www.wikidata.org/wiki/Q192588","display_name":"Relational database management system","level":3,"score":0.41646867990493774},{"id":"https://openalex.org/C67186912","wikidata":"https://www.wikidata.org/wiki/Q367664","display_name":"Data modeling","level":2,"score":0.4104936420917511},{"id":"https://openalex.org/C80444323","wikidata":"https://www.wikidata.org/wiki/Q2878974","display_name":"Theoretical computer science","level":1,"score":0.39559197425842285},{"id":"https://openalex.org/C23123220","wikidata":"https://www.wikidata.org/wiki/Q816826","display_name":"Information retrieval","level":1,"score":0.32993799448013306},{"id":"https://openalex.org/C199360897","wikidata":"https://www.wikidata.org/wiki/Q9143","display_name":"Programming language","level":1,"score":0.24693375825881958},{"id":"https://openalex.org/C154945302","wikidata":"https://www.wikidata.org/wiki/Q11660","display_name":"Artificial intelligence","level":1,"score":0.15108650922775269},{"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/C94625758","wikidata":"https://www.wikidata.org/wiki/Q7163","display_name":"Politics","level":2,"score":0.0},{"id":"https://openalex.org/C199539241","wikidata":"https://www.wikidata.org/wiki/Q7748","display_name":"Law","level":1,"score":0.0}],"mesh":[],"locations_count":3,"locations":[{"id":"doi:10.1109/tkde.2016.2588490","is_oa":false,"landing_page_url":"https://doi.org/10.1109/tkde.2016.2588490","pdf_url":null,"source":{"id":"https://openalex.org/S30698027","display_name":"IEEE Transactions on Knowledge and Data Engineering","issn_l":"1041-4347","issn":["1041-4347","1558-2191","2326-3865"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310320439","host_organization_name":"IEEE Computer Society","host_organization_lineage":["https://openalex.org/P4310320439","https://openalex.org/P4310319808"],"host_organization_lineage_names":["IEEE Computer Society","Institute of Electrical and Electronics Engineers"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"IEEE Transactions on Knowledge and Data Engineering","raw_type":"journal-article"},{"id":"pmh:oai:iris.unito.it:2318/1634571","is_oa":true,"landing_page_url":"http://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=69","pdf_url":"http://hdl.handle.net/2318/1634571","source":{"id":"https://openalex.org/S4306400637","display_name":"Institutional Research Information System University of Turin (University of Turin)","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"host_organization":"https://openalex.org/I55143463","host_organization_name":"University of Turin","host_organization_lineage":["https://openalex.org/I55143463"],"host_organization_lineage_names":[],"type":"repository"},"license":"other-oa","license_id":"https://openalex.org/licenses/other-oa","version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"","raw_type":"info:eu-repo/semantics/article"},{"id":"pmh:oai:research-repository.griffith.edu.au:10072/100475","is_oa":false,"landing_page_url":"http://hdl.handle.net/10072/100475","pdf_url":null,"source":null,"license":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"","raw_type":"Journal article"}],"best_oa_location":{"id":"pmh:oai:iris.unito.it:2318/1634571","is_oa":true,"landing_page_url":"http://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=69","pdf_url":"http://hdl.handle.net/2318/1634571","source":{"id":"https://openalex.org/S4306400637","display_name":"Institutional Research Information System University of Turin (University of Turin)","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"host_organization":"https://openalex.org/I55143463","host_organization_name":"University of Turin","host_organization_lineage":["https://openalex.org/I55143463"],"host_organization_lineage_names":[],"type":"repository"},"license":"other-oa","license_id":"https://openalex.org/licenses/other-oa","version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"","raw_type":"info:eu-repo/semantics/article"},"sustainable_development_goals":[],"awards":[],"funders":[{"id":"https://openalex.org/F4320309746","display_name":"Compagnia di San Paolo","ror":"https://ror.org/00d1b1c41"}],"has_content":{"grobid_xml":true,"pdf":true},"content_urls":{"pdf":"https://content.openalex.org/works/W2519931105.pdf","grobid_xml":"https://content.openalex.org/works/W2519931105.grobid-xml"},"referenced_works_count":30,"referenced_works":["https://openalex.org/W182552746","https://openalex.org/W1536826708","https://openalex.org/W1549387132","https://openalex.org/W1599633142","https://openalex.org/W1863013955","https://openalex.org/W1971602700","https://openalex.org/W1988991358","https://openalex.org/W1992732065","https://openalex.org/W2004851292","https://openalex.org/W2005186460","https://openalex.org/W2017228277","https://openalex.org/W2028472574","https://openalex.org/W2029209936","https://openalex.org/W2032513332","https://openalex.org/W2043707684","https://openalex.org/W2048715330","https://openalex.org/W2095119094","https://openalex.org/W2102023823","https://openalex.org/W2116132637","https://openalex.org/W2119368079","https://openalex.org/W2140422321","https://openalex.org/W2154644815","https://openalex.org/W2165467455","https://openalex.org/W2165620568","https://openalex.org/W2167350691","https://openalex.org/W2185907055","https://openalex.org/W2288657397","https://openalex.org/W4237036854","https://openalex.org/W4254419736","https://openalex.org/W6684815006"],"related_works":["https://openalex.org/W90961951","https://openalex.org/W1526523172","https://openalex.org/W2118401712","https://openalex.org/W207305439","https://openalex.org/W1579443643","https://openalex.org/W3023408063","https://openalex.org/W2376710457","https://openalex.org/W2139205714","https://openalex.org/W2397160827","https://openalex.org/W2024777025"],"abstract_inverted_index":{"Now-related":[0],"temporal":[1,24,141,190],"data":[2,33,58,77,122],"play":[3],"an":[4,60,170],"important":[5],"role":[6],"in":[7,23,111,116,129,143],"many":[8],"applications.":[9],"Clifford":[10],"et":[11],"al.'s":[12],"approach":[13,68,92,153,183],"is":[14,59,103,184,196],"a":[15,52,72,79,124,159,185],"milestone":[16],"to":[17,55,97,107,188,198],"model":[18,84,137],"the":[19,38,49,65,112,117,130,138,144,166,179],"semantics":[20,39,74],"of":[21,40,51,140,151,165,173],"`now'":[22],"relational":[25,28,53,86,191],"databases.":[26],"Several":[27],"representation":[29,82],"models":[30],"for":[31,75,88,146],"now-related":[32,57,76,121,147],"have":[34],"been":[35,45],"presented;":[36],"however,":[37],"such":[41],"representations":[42],"has":[43],"not":[44,104],"explicitly":[46,136],"studied.":[47],"Additionally,":[48,90],"definition":[50],"algebra":[54],"query":[56],"open":[61],"problem.":[62],"We":[63],"propose":[64],"first":[66],"integrated":[67],"that":[69,181],"provides":[70],"both":[71,157],"neat":[73],"and":[78,85,119,163,168],"compact":[80],"1NF":[81],"(data":[83],"algebra)":[87,167],"them.":[89],"our":[91,152,182],"also":[93,155],"extends":[94],"current":[95,189],"approaches":[96],"consider":[98],"(i)":[99],"domains":[100],"where":[101],"it":[102],"always":[105],"possible":[106],"know":[108],"when":[109],"changes":[110],"world":[113],"are":[114,154],"recorded":[115],"database":[118],"(ii)":[120],"with":[123,200],"bound":[125],"on":[126],"their":[127],"persistency":[128],"future.":[131],"To":[132],"do":[133],"so,":[134],"we":[135],"notion":[139],"indeterminacy":[142],"future":[145],"data.":[148],"The":[149],"properties":[150],"analyzed":[156],"from":[158,169],"theoretical":[160],"(semantic":[161],"correctness":[162],"reducibility":[164],"experimental":[171],"point":[172],"view.":[174],"Experiments":[175],"show":[176],"that,":[177],"despite":[178],"fact":[180],"major":[186],"extension":[187],"approaches,":[192],"no":[193],"significant":[194],"overhead":[195],"added":[197],"deal":[199],"`now'.":[201]},"counts_by_year":[{"year":2025,"cited_by_count":2},{"year":2024,"cited_by_count":1},{"year":2022,"cited_by_count":3},{"year":2020,"cited_by_count":2},{"year":2019,"cited_by_count":3},{"year":2018,"cited_by_count":4}],"updated_date":"2025-11-06T03:46:38.306776","created_date":"2025-10-10T00:00:00"}