03812nam 22006375 450 99646573400331620200629143033.03-540-47110-310.1007/3-540-55493-9(CKB)1000000000233818(SSID)ssj0000325081(PQKBManifestationID)11234406(PQKBTitleCode)TC0000325081(PQKBWorkID)10321009(PQKB)10263356(DE-He213)978-3-540-47110-3(PPN)15516452X(EXLCZ)99100000000023381820121227d1992 u| 0engurnn|008mamaatxtccrThe Nested Universal Relation Database Model[electronic resource] /by Mark Levene1st ed. 1992.Berlin, Heidelberg :Springer Berlin Heidelberg :Imprint: Springer,1992.1 online resource (X, 182 p.) Lecture Notes in Computer Science,0302-9743 ;595Bibliographic Level Mode of Issuance: Monograph3-540-55493-9 The underlying database models -- The null extended nested relational model -- Null extended data dependencies and the extended chase -- A universal relation model for a nested database -- A universal relation model for a single nested relation -- Concluding remarks and ongoing research.This monograph describes a method of data modelling whose basic aim is to make databases easier to use by providing them with logical data independence. To achieve this, the nested UR (universal relation) model is defined by extending the classical UR model to nested relations. Nested relations generalize flat relations and allow hierarchically structured objects to be modelled directly, whereas the classical UR model allows the user to view the database as if it were composed of a single flat relation. The author presents a comprehensive formalisation of the nested relational model, which incorporated null values into the model. Functional data dependencies and the classical notion of lossless decomposition are extended to nested relations and an extended chase procedure is defined to test the satisfaction of the data dependencies. The nested UR model is defined, and the classical UR model is shown to be a special case of the nested model.This implies that an UR interface canbe implemented by using the nested UR model, thus gaining the full advantages of nested relations over flat relations.Lecture Notes in Computer Science,0302-9743 ;595Data structures (Computer science)Database managementComputersSoftware engineeringData Structures and Information Theoryhttps://scigraph.springernature.com/ontologies/product-market-codes/I15009Database Managementhttps://scigraph.springernature.com/ontologies/product-market-codes/I18024Computation by Abstract Deviceshttps://scigraph.springernature.com/ontologies/product-market-codes/I16013Software Engineeringhttps://scigraph.springernature.com/ontologies/product-market-codes/I14029Data structures (Computer science).Database management.Computers.Software engineering.Data Structures and Information Theory.Database Management.Computation by Abstract Devices.Software Engineering.005.75/6Levene Markauthttp://id.loc.gov/vocabulary/relators/aut311716BOOK996465734003316Nested universal relation database model1492489UNISA01025nam a22002651i 450099100398179970753620030929152113.0031111s1976 it |||||||||||||||||ita b12502078-39ule_instARCHE-053534ExLDip.to LingueitaA.t.i. Arché s.c.r.l. Pandora Sicilia s.r.l.843.91Mossetto Campra, Anna Paola457730Invito alla lettura di André Gide /Anna Paola Campra MossettoMilano :Mursia,1976152 p. ;17 cmInvito alla lettura.Sezione straniera ;9Gide, AndréOpereGuide criticheGide, AndréFortunaStudi.b1250207802-04-1413-11-03991003981799707536LE012 848.91 GID CAM12012000155213le012-E0.00-l- 00000.i1293876213-11-03Invito alla lettura di André Gide182951UNISALENTOle01213-11-03ma -itait 01