Database-Oracle [3i Infotech Placement]: Sample Questions 48 - 49 of 132

Glide to success with Doorsteptutor material for competitive exams : get questions, notes, tests, video lectures and more- for all subjects of your exam.

Question 48

Oracle

Question

MCQ▾

In mapping of ERD to DFD

Choices

Choice (4)

a.

Relations in ERD has 1 to 1 correspondence to processes in DFD

b.

Entities in ERD should correspond to an existing entity/store in DFD

c.

Relationships in ERD has 1 to 1 correspondence to flows in DFD

d.

Entity in DFD is converted to attributes of an entity in ERD

Answer

b.

Explanation

  • DFD- Data Flow Diagram- shows how data enters a system, are transformed in that system, and how it is stored in it.
  • ERD - Entity Representation Diagram- represents the entity model and will show what a system or a database will look like but not explain how to implement it.
  • Entities in ERD should correspond to an existing entity/store in DFD.

ERD

  • ERD is a snapshot of data structures.
  • Shows entities (tables) in a database and relationships between tables within that database.
  • For a good database design it is essential to have an ERD.

DFD

  • DFD is a graphical representation of the “flow” of data through an information system.
  • It views a system as a function that transforms the input into desired output.

Question 49

Oracle

Question

MCQ▾

Can we use a RESTRICTED packaged procedure in WHEN_TEXT_ITEM trigger?

Choices

Choice (4)

a.

No

b.

Yes

c.

All of the above

d.

None of the above

Answer

a.

Explanation

  • No, we cannot use a RESTRICTED packaged procedure in WHEN_TEXT_ITEM trigger.
  • Restricted package procedure affect the basic functions of SQL ⚹ From.
  • It cannot be use in any triggers except key trigger.

    Bellow the list of restricted packaged procedure:

    • Up
    • Execute Query
    • Message
    • Exit_form
    • Post

Developed by: