000 03066nam a22005055i 4500
001 978-3-540-47110-3
003 DE-He213
005 20160624102020.0
007 cr nn 008mamaa
008 121227s1992 gw | s |||| 0|eng d
020 _a9783540471103
_9978-3-540-47110-3
024 7 _a10.1007/3-540-55493-9
_2doi
050 4 _aQA76.9.D3
072 7 _aUN
_2bicssc
072 7 _aUMT
_2bicssc
072 7 _aCOM021000
_2bisacsh
082 0 4 _a005.74
_223
245 1 4 _aThe Nested Universal Relation Database Model
_h[electronic resource] /
_cedited by M. Levene.
260 1 _aBerlin, Heidelberg :
_bSpringer Berlin Heidelberg,
_c1992.
264 1 _aBerlin, Heidelberg :
_bSpringer Berlin Heidelberg,
_c1992.
300 _aX, 182 p.
_bonline resource.
336 _atext
_btxt
_2rdacontent
337 _acomputer
_bc
_2rdamedia
338 _aonline resource
_bcr
_2rdacarrier
347 _atext file
_bPDF
_2rda
490 1 _aLecture Notes in Computer Science,
_x0302-9743 ;
_v595
505 0 _aThe 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.
520 _aThis 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.
650 0 _aComputer science.
650 0 _aSoftware engineering.
650 0 _aDatabase management.
650 1 4 _aComputer Science.
650 2 4 _aDatabase Management.
650 2 4 _aComputation by Abstract Devices.
650 2 4 _aSoftware Engineering.
700 1 _aLevene, M.
_eeditor.
710 2 _aSpringerLink (Online service)
773 0 _tSpringer eBooks
776 0 8 _iPrinted edition:
_z9783540554936
786 _dSpringer
830 0 _aLecture Notes in Computer Science,
_x0302-9743 ;
_v595
856 4 0 _uhttp://dx.doi.org/10.1007/3-540-55493-9
942 _2EBK5981
_cEBK
999 _c35275
_d35275