3i Infotech Papers: Sample Questions 146 - 147 of 1245

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Question number: 146

» Database » MySQL

Essay Question▾

Describe in Detail

What is system catalog or catalog relation? How is better known as?

Explanation

Definethe system Catalog.

Definethe System Catalog.

Definethe system Catalog.

  • A DBMS maintains information about each of relation and index that it contains.

  • The metadata is the information stored in a collection of relations maintained by the system

  • It is also called data dictionary.

  • The catalog relations are also called the system catalog or the data dictionary.

  • The system catalog is sometimes also referred to as metadata (data about data).

  • The system catalog is generally used only for query optimization.

  • It is also known as metadata.

Question number: 147

» Database » Oracle

MCQ▾

Question

SUBSTR (SQUARE ANS ALWAYS WORK HARD, 14,6) will return

Choices

Choice (4) Response

a.

ALWAYS

b.

ALWAY

c.

S ALWA

d.

Question does not provide sufficient data or is vague

Answer

a.

Explanation

  • SUBSTR (SUBSTRING) function extracts a portion of a string from a string of characters.

    Syntax:

  • SUBSTR (source_string, starting_position, [length] );

  • The string_position is the position in the source_string we want to start extracting characters.

  • source_string is always ‘1’, NOT ‘0’

    • starting_position is 0, then SUBSTR treats start_position as 1 (i.e.: the first position in the string).

    • starting_position is a positive number, then SUBSTR starts from the beginning of the string.

    • starting_position is a negative number, then SUBSTR starts from the end of the source_string and counts backwards.

  • The length parameter is optional, and specifies the number of characters to extract.

  • If length is a negative number, then SUBSTR will return NULL value.

Table of the square ans always work hard

Table of the square ans always work hard

S

Q

U

A

R

E

A

N

S

A

L

W

A

Y

S

W

O

R

K

H

A

R

D

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

  • So, SUBSTR (SQUARE ANS ALWAYS WORK HARD, 14,6) will return: ALWAYS.