DBMS-Relational Algebra and Calculus

DBMS-Relational Algebra and Calculus
11. A table can have only one alternate key
  • TRUE
  • FALSE
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12. A table can have only one candidate key.
  • TRUE
  • FALSE
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13. The foreign key and the primary key should be defined on the same underlying domain.
  • TRUE
  • FALSE
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14. A relation always has a unique identifier.
  • TRUE
  • FALSE
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15. Primary key performs the unique identification function in a relational database model.
  • TRUE
  • FALSE
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16. In a reality, NULL is not a value, but rather the absence of a value.
  • TRUE
  • FALSE
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17. Relational database is a finite collection of relations and a relation in terms of domains, attributes, and cuples.
  • TRUE
  • FALSE
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18. Atomic means that each value in the domain is indivisible to the relational model.
  • TRUE
  • FALSE
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19. Superkey is an attribute, or set of attributes, that uniquely indentifies a tuple within a relation
  • TRUE
  • FALSE
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20. Codd defined well-formed formulas (WFFs).
  • TRUE
  • FALSE
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