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Author Question: Which of the following properties should be satisfied when the identifier of the entity type becomes ... (Read 43 times)

Tazate

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on: Jul 7, 2018
Which of the following properties should be satisfied when the identifier of the entity type becomes the primary key of the corresponding relation?
 
  A) The value of the key must uniquely identify every row in the relation.
  B) The key should serve as a foreign key in at least two other relations.
  C) The key must be a composite of a primary key and a secondary key.
  D) The key should be an intelligent key.
  E) The key should allow for null values.

Question 2

Modeling deliverables from project activities using object-oriented modeling include:
 
  A) structure charts and data flow diagrams.
  B) dialogue diagrams and object reference charts.
  C) decision tables and object status diagrams.
  D) data-flow and entity-relationship diagrams and repository descriptions.
  E) dialogue diagrams, Structured English representations, and structure charts.


bpool94

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Reply #1 on: Jul 7, 2018
Answer to Question 1

A
Explanation: A) A primary key is an attribute whose value is unique across all occurrences of a relation.
CL

Answer to Question 2

D
Explanation: D) Unique to UML is how tightly linked these three deliverables are to each other.
CL


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