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Table 1 Summary of patterns to calculate NS

From: A novel approach for learning ontology from relational database: from the construction to the evaluation

Patterns Acronym
Table without FKs NTDFK
Table with one FK NTFK
Table with more than 2 FKs NTMTWOFK
Tables that contain exactly 2 foreign keys with presence of independent attributes NTEXTWOFK
Attributes that are FK + NULL + Not UNIQUE NAFKNNU
Attributes that are FK + NOT NULL + NOT UNIQUE NAFKNNNU
Attributes that are FK + NOT NULL + UNIQUE NAFKNNU
Attributes that are FK + NOT NULL + UNIQUE + NOT PK (FK is not equal to the PK) NANNUNPK
Attribute (neither PK nor FK) NA
Attribute + NOT NULL NAN
Attribute with constraint with an integer greater than 0 NACHECK
CHECK constraint with enumeration
CHECK constraint
Attribute with Default Value constraint NADef
Tables with tables share the same primary key NTSAMEPK
FK is a reference to the same table NUnaryRel
FK that is a reference to the same table, but it is accompanied by a trigger ON DELETE CASCADE NTrRel