Définition
Dataredundancywillhindertheintegrityofthedatainthedatabase, andwillalsocauseawasteofstoragespace.Toreducedataredundancyasmuchaspossibleisoneofthemaingoalsofdatabasedesign.Oneofthemainideasofthenormalizationtheoryofrelationalmodel (hereinafterreferredtoasNFtheory) istheprincipleofleastredundancy, thatis, thestandardizedrelationalmodelshouldhavetheleastredundancyinacertainsense.However, NFtheoryhasnostandardconceptavailable.Accordingtotheprincipleofequivalence, theremaybeseveralredundantdefinitionsunderdifferentpremisessuchasuniversalrelationassumptionornot.
comparaison en anglais
redondancede;redondance;redondant;degré de redondance;
explication
1, referstoaspecialemotionininterpersonalcommunicationThewayofexpressionistoconveysincereaffectionwithseeminglyredundantandirrelevantnonsense, andcausetheinteractionandreturnofemotions.Whenrelativesandfriendsmeetindailylife, knowingthattheyhaveeaten, theystillkindlyask: "Haveyoueaten?" Whentheirchildrengoout, parentswillrepeatedlywarn: "Becarefulwhencrossingthestreet" Thesebehaviorsaremanifestationsofredundancy.Duetothenarrowingofthescopeofactivitiesandtheincreaseofpsychologicalloneliness, theelderlyespeciallyhopethatacaringpersonwillnagwiththem, son ...