3i Infotech Placement: Sample Questions 384 - 385 of 1245

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Question 384

Question

MCQ▾

Which of the following is not correct about a View?

Choices

Choice (4)

a.

Used to protect some of the columns of a table from other users

b.

Used to hide complexity of a query

c.

Occupies data storage space

d.

Used to hide complexity of calculations

Answer

c.

Explanation

Understanding of View
  • View is logical representation of table or combination of tables.
  • Derive its data from the table on which it is based.
  • Essentially is result set of a stored query on the data.
  • It is virtual table compound or collated dynamically from data in the database when view is requested.

Advantages of view:

  • Represents a subset of data contained table.
  • Join and simplify multiple tables into a single virtual table.
  • Hides the complexity of data.
  • Take very little space, it contains only definition of view, not a copy of all the data.
  • Hides complexity of a calculations.
  • Protects some of the columns of a table from other users.

Question 385

Edit

Statement

True-False▾

The following parameters are optional in init. ora parameter file

DB_BLOCK_SIZE,

PROCESS

Answer

FALSE

Explanation

DB_BLOCK_SIZE and PROCESS parameters in the init. ora is the most important and are compulsory

DB_BLOCK_SIZE

  • Specifies the size of oracle database blocks.
  • Typical values are 4096 and 8192.
  • This parameter must be a multiple of the physical block size at the device level.
  • Can be set only during DB creation time.

PROCESS

  • Specifies the maximum number of operating system user processes that can connect to oracle.
  • Value includes all background processes as locks, parallel execution processes.
  • The default value of the SESSIONS and TRANSACTIONS parameter derived from this parameter.
  • Changing the value of PROCESSES requires re-evaluating he value of derived parameters.

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