Question:

1. Following features will not simplify the ER data model for decision support systems.

a. Extended ER model

b. Dimensional Model

c. Data vault

d. De-Normalization

e. All of the above

2. Which of the following schemas does not have hierarchies

a. Snow flake schema

b. Snow schema

c. Star flake schema

d. Galaxy Schema

e. All of the above

3. Which of the following is an atomic grain

a. Individual transaction

b. Daily aggregates

c. Monthly aggregated

d. Snapshots

e. None of the above

4. Which of the following is an example of grain

a. Entry from cache register

b. Boarding pass to get on a flight

c. Sensor reading per minute for a sensor

d. Student enrolled in a course

e. All of the above

5. Which statement is true for aggregation

a. Hides crucial facts

b. Does not work for repetitive queries

c. Can create weekly sales data from monthly sales

d. A microscopic view of data

e. All of the above

6. Which of the following are dimensions

a. Product

b. Quantity sold

c. Time

d. Account number

7. Which of the following are un answered questions of ER modeling (2)

a. Which table is important

b. Relationships between the tables

c. Which table contain numeric data

d. All of above

8. Star Schema results in:

a. Simplified physical model

b. Fewer tables

c. Fewer joins resulting in higher performance

d. Need for additional space

e. All of the above

9. Which of the following are features of Dimensional Modeling

a. Single path between any two tables

b. All relationships are 1:M

c. Supports OLAP operations

d. Keys are usually system generated

e. All of the above

10. The characteristics of data warehouse are:

a. Ideal environment for data analysis

b. Fluid, flexible and interactive

c. 100 % user driven

d. Provides the ability to discover complex, unpredictable questions

e. All of the above

11. What of following applies to fact-less fact table

a. Captures relationship between dimensions

b. Use a dummy fact column that always has a value 1

c. A table without a numeric column

d. Kind of like periodic snapshot of fact

e. All of the above

12. Requirement analysis document should include

a. Purpose of data warehouse

b. End user applications and how they analyze data

c. Location of data sources and data structures used

d. Bus Matrix

e. All of the above

13. Reasons of moving to data warehouse is

a. Processing huge amount of data

b. Providing interactive analysis

c. Lower cost

d. None of the above

e. All of the above

14. In data Warehouse data will be collected in terms of

a. Dimensions

b. Hierarchies

c. Facts

d. All of the above

15. The numbers that users analyze are called

a. Dimensions

b. Hierarchies

c. Facts

d. All of the above

16. The part of a junk dimension are

a. Code of a city entered incorrect

b. Payment Method

c. No changes needed elsewhere in dimension

d. Dimension referenced many times in fact table

e. All of the above

17. The part of a Role playing dimension are

a. Code of a city entered incorrect

b. Payment Method

c. No changes needed elsewhere in dimension

d. Dimension referenced many times in fact table

e. All of the above

18. What does a dimension table contains

a. Hierarchies

b. Foreign keys

c. Categories

d. Primary keys

e. All of the above

19. Which type of relationship star schema contains between fact table and every dimension table

a. 1:1

b. 1:M

c. M:1

d. M:N

20. Which facts can be derived from other attributes

a. Additive

b. Semi additive

c. Summary

d. Base

e. None of the above

Please provide brief explanation. Thank you!