3i Infotech Placement: Sample Questions 1120 - 1121 of 1245

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Question 1120

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Describe in Detail

Essay▾

Explain Normalization and Denormalization with examples.

Explanation

Normalization

  • It is the process of organizing data into related table.
  • To normalize database, we divide database into tables and establish relationships between the tables.
  • It reduces redundancy. It is done to improve performance of query.

    Steps of normalization:

  • First Normal form
    • Entities of the table must have unique identifier or entity key.
    • Second Normal Form
    • All the attributes of the table must depend on the entity key for that entity.
    • Third Normal Form
    • All attributes that are not part of the key must not depend on any other non-key attributes.

    Example of Normalization:

Normalization Process

De-normalization

  • The process of adding redundant data to get rid of complex join, in order to optimize database performance.
  • This is done to speed up database access by moving from higher to lower form of normalization.

Example of De-normalization

Example of De-Normalization

Question 1121

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Write in Short

Short Answer▾

A dishonest shopkeeper professes to sell pulses at the cost price, but he uses a false weight of 950gm. What will be his gain for a kg?

Explanation

A dishonest shopkeeper professes to sell pulses at the cost price, but he uses a false weight of 950gm.

So, true value = 1000 gm

m

Now,

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