Dimensional Data modelling

Question 1

The process of organizing and preparing data for analysis is called as

Answer 1

data staging

Question 2

which of these ensures data becomes consistent, relevant and free from ambiguities

a) data provisioning
b) data gathering
c) data staging

Answer 2

c)data staging

Question 3

defining data and their relationships are called

Answer 3

data modeling

Question 4

data warehouse has ________tables

Answer 4

denormalized

Question 5

The tables in DW are ______-only

Answer 5

read-only hence normalization not required

Question 6

DB architecture with summarised, harmonized, cleansed, consolidated data is called

Answer 6

data warehouse

Question 7

operational data –txn data are both one and the same

T/F

Answer 7

T

Question 8

Detailed view of the fact table is called

Answer 8

dimensional table

Question 9

Number of dimension in star schema is fixed

T/F

Answer 9

F depends on analytics requirements

Question 10

Why is star schema called multidimensional structure

Answer 10

number of dimesnions is not fixed

Question 11

Default numnber of dimensions in star schema is

Answer 11

3

Question 12

fact table contans ________& _______data

Answer 12

txn and organizational data

Question 13

the fact table contains txn attributes also called as

Answer 13

key /measures

Question 14

detailed view of fact is called

Answer 14

dimensional tables

Question 15

fact table has separate currency unit as attribute T/F

Answer 15

T. to store key measures in different currenncies

Question 16

data in __-table without data in __ table is not useful

Answer 16

fact , dimension

Question 17

data package dimension contains

Answer 17

details when txn is loaded in to fact table

time stamp ,loadingnumber

Question 18

data in __-table without data in __ table is not useful

Answer 18

fact, dimension

Question 19

data package dimension contains

Answer 19

details when txn is loaded into fact table

time stamp, loading number

Question 20

IS DATA DIMENSION PACKAGE USED FOR ANALYTICS

Answer 20

NO..simply used for maintenance ,keep a check rogue loads

Question 21

IS DATA DIMENSION PACKAGE USED FOR ANALYTICS

Answer 21

NO..simply used for maintenance, keep a check rogue loads

Question 22

UOM and currency key is in text

Answer 22

us dollars, kilograms lbs etc

Question 23

the rogue load concept is with respect to the fact table

t/f

Answer 23

t

Question 24

_ TO _ relational between dimension and fact table

Answer 24

1: M

Question 25

adv of star schema

Answer 25

simple: 1 fact table many dimensions tab

only 1 join easy query

Question 26

disadvantages of star schema

Answer 26

country state zip problem
alphanumeric foreign key –slower
does not support multiple languages

Question 27

HISTORIZATION

Answer 27

history showing changes in attribute

Question 28

does star schema support historization

Answer 28

No

Question 29

Hierarchy in dimension table causes

Answer 29

anomalies.especially when we have 2 hierarchies

Question 30

___________- anomaly is caused due to hierarchy

Answer 30

update

Question 31

which layer in data warehouse has read optimise data cube for querying

Answer 31

reporting layer