Database [3i Infotech Placement]: Sample Questions 280 - 281 of 294

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Question 280

Database

Question

MCQ▾

Which of the following is TRUE

1. Host variables are declared anywhere in the program

2. Host variables are declared in the DECLARE section

Choices

Choice (4)

a.

Only 2 is TRUE

b.

Only 1 is TRUE

c.

1 & 2 are TRUE

d.

1 & 2 are FALSE

Answer

a.

Explanation

  • Host variable are data items defined a COBOL program.
  • Host variable is used to pass values to and receive values from a database.
  • Host variables can be defined in the File Section, Working-Storage Section, Local-Storage Section of the COBOL program.
  • Host variable declarations are embedded SQL statements “BEGIN DECLARE SECTION” and “END DECLARE SECTION”

Host Variable Are Used in Two Way

Input host variables

  • Input host variables specify data that will be transfer from the COBOL program to the database.

Output host variables

  • Output host variables hold data that is returned to the COBOL program from the database.

When we use the host variable in a SQL statement before we must declare it.

Question 281

Database
Edit

Describe in Detail

Essay▾

What is the job of the information stored in data-dictionary?

Explanation

  • The information in the data dictionary validates the existence of the object, provides access to them, and acts as actual physical storage location.
  • Not only RDBMS takes care of locating data it also determines an optimal access path to store or retrieve the data
  • A first step in analysing a system of objects with which users interact is to identify each object and its relationship to other objects.
  • This is called data modelling- a picture of object relationships.
  • Programs that use the data model, when developing a data dictionary can be consulted to understand where a data item fits in the structure, what values it may contain, and what the data item means in real world.
  • For example, a bank or group of banks could model the data objects involved in consumer banking. They could then provide a data dictionary for a bank՚s programmers.
  • The data dictionary would describe each of the data items in its data model for consumer banking.

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