000 | 02921nam a22005175i 4500 | ||
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001 | 978-3-540-46507-2 | ||
003 | DE-He213 | ||
005 | 20160624102015.0 | ||
007 | cr nn 008mamaa | ||
008 | 121227s1991 gw | s |||| 0|eng d | ||
020 |
_a9783540465072 _9978-3-540-46507-2 |
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024 | 7 |
_a10.1007/3-540-54919-6 _2doi |
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050 | 4 | _aQA76.9.D3 | |
072 | 7 |
_aUN _2bicssc |
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072 | 7 |
_aUMT _2bicssc |
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072 | 7 |
_aCOM021000 _2bisacsh |
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082 | 0 | 4 |
_a005.74 _223 |
245 | 1 | 4 |
_aThe Problem of Incomplete Information in Relational Databases _h[electronic resource] / _cedited by Gösta Grahne. |
260 | 1 |
_aBerlin, Heidelberg : _bSpringer Berlin Heidelberg, _c1991. |
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264 | 1 |
_aBerlin, Heidelberg : _bSpringer Berlin Heidelberg, _c1991. |
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300 |
_aVIII, 164 p. _bonline resource. |
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336 |
_atext _btxt _2rdacontent |
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337 |
_acomputer _bc _2rdamedia |
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338 |
_aonline resource _bcr _2rdacarrier |
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347 |
_atext file _bPDF _2rda |
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490 | 1 |
_aLecture Notes in Computer Science, _x0302-9743 ; _v554 |
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505 | 0 | _aRelational databases -- Semantic aspects of incomplete information -- Syntactic and algorithmic aspects of incomplete information -- Computational complexity aspects of incomplete information -- Some conclusive aspects. | |
520 | _aIn a relational database the information is recorded as rows in tables. However, in many practical situations the available information is incomplete and the values for some columns are missing. Yet few existing database management systems allow the user to enter null values in the database. This monograph analyses the problems raised by allowing null values in relational databases. The analysis covers semantical, syntactical, and computational aspects. Algorithms for query evaluation, dependency enforcement and updates in the presence of null values are also given. The analysis of the computational complexity of the algorithms suggests that from a practical point of view the database should be stored as Horn tables, which are generalizations of ordinary relations, allowing null values and Horn clause-like restrictions on these null values. Horn tables efficiently support a large class of queries, dependencies and updates. | ||
650 | 0 | _aComputer science. | |
650 | 0 | _aComputer software. | |
650 | 0 | _aDatabase management. | |
650 | 0 | _aArtificial intelligence. | |
650 | 1 | 4 | _aComputer Science. |
650 | 2 | 4 | _aDatabase Management. |
650 | 2 | 4 | _aAlgorithm Analysis and Problem Complexity. |
650 | 2 | 4 | _aArtificial Intelligence (incl. Robotics). |
700 | 1 |
_aGrahne, Gösta. _eeditor. |
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710 | 2 | _aSpringerLink (Online service) | |
773 | 0 | _tSpringer eBooks | |
776 | 0 | 8 |
_iPrinted edition: _z9783540549192 |
786 | _dSpringer | ||
830 | 0 |
_aLecture Notes in Computer Science, _x0302-9743 ; _v554 |
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856 | 4 | 0 | _uhttp://dx.doi.org/10.1007/3-540-54919-6 |
942 |
_2EBK5808 _cEBK |
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999 |
_c35102 _d35102 |