{"product_id":"9783540554936","title":"Lecture Notes in Computer Science","description":"\u003ch1\u003eLecture Notes in Computer Science\u003c\/h1\u003e \u003ch2\u003eLevene, Mark\u003c\/h2\u003e \u003cp\u003eThis monograph describes a method of data modelling whose\nbasic aim is to   make databases easier to use by providing\nthem with logical data            independence. To achieve this, the\nnested UR (universal relation) model is  defined by extending\nthe classical UR model to nested relations. Nested     relations\ngeneralize flat relations and allow hierarchically\nstructured objects to be modelled directly, whereas the\nclassical UR model allows the  user to view the database as\nif it were composed of a single flat relation. The author\npresents a comprehensive formalisation of the                    nested\nrelational model, which incorporated null values into the\nmodel. Functional data dependencies and the classical notion\nof lossless           decomposition are extended to nested relations\nand an extended chase        procedure is defined to test the\nsatisfaction of the data dependencies. The nested UR model\nis defined, and the classical UR model is shown to be       a\nspecial case of the nested model.This implies that an UR\ninterface canbe implemented by using the nested UR model,\nthus gaining the full          advantages of nested relations over\nflat relations.\u003c\/p\u003e \u003ch3\u003eDetails\u003c\/h3\u003e \u003cp\u003ePublished by: Springer\u003c\/p\u003e \u003cp\u003ePublication Date: 1992-05-20\u003c\/p\u003e \u003cp\u003eFormat: Paperback\u003c\/p\u003e \u003cp\u003eISBN-13: 9783540554936\u003c\/p\u003e \u003cp\u003eDOI: 10.1007\/3-540-55493-9\u003c\/p\u003e \u003cp\u003eDimensions: 235cm x155cm\u003c\/p\u003e \u003cp\u003ePages: 182\u003c\/p\u003e ","brand":"Springer Berlin Heidelberg","offers":[{"title":"Default Title","offer_id":45369974816908,"sku":"9783540554936","price":49.49,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0710\/9545\/1788\/files\/9783540554936.jpg?v=1771506121","url":"https:\/\/fh90cf-fv.myshopify.com\/products\/9783540554936","provider":"Late Knight Books and Services, LLC","version":"1.0","type":"link"}