Datawarehousing Quiz

I am listing down some of the datawarehousing / Business intelligence questions in form of quiz that can be helpful to you during interview. 

1. OLAP is an acronym for
1. Online Analytical Processing
2. Online Analysis Process
3. Online Arithmetic Processing
4. Object Linking and Processing

 
 

2. What is a Data warehouse
1. A database application that searches for hidden patterns in a database.
2. A database designed to support decision making in organizations. It is batch updated and structured for rapid on-line queries and managerial summaries
3. An interactive computer based system which helps decision makers utilize data and models to identify and solve problems and make decisions.

 
 

3. The following is the characteristic(s) of data in a data warehouse
1. Subject Oriented
2. Non-Volatile
3. Time-Variant
4. Integrated
5. All the above

 
 

4. Which of the following is false
1. Data Warehouse is designed for query and analysis
2. Data Warehouse is designed for transaction processing
3. Data Warehouse consolidates data from several sources
4. Data Warehouse maintains the records of both historical and the current data

 
 

5. The data in Data Warehouse is generally
1. Clean Data
2. Dirty Data
3. Clean and Dirty Data
4. None of above

 

6. What is Metadata
1. Metadata contains the relationship between Dimension and Fact Tables
2. Metadata describes data and other structures, such as objects, business rules, and processes
3. Metadata stores the aggregation information
4. Metadata contains only business rules

 

7. Multidimensional data can be queried and manipulated using
1. T-SQL
2. MDX
3. MDAC
4. OWC

 

 

8. The following is not the characteristic of Dimension table
1. Describes business entities
2. Presents data organized into Hierarchies
3. Describes data in the fact table
4. Referential integrity need not be maintained between dimension tables and the fact table

 

9. Different Storage Modes used for storage of cubes are
1. MOLAP
2. ROLAP
3. HOLAP
4. All the above

 

10. Which of the following best describes the Fact table
1. Contains only measures
2. Contains only keys that join to Dimension Tables
3. Contains measures and keys that join to Dimension tables
4. None of the above

 

11. Which of the following is false
1. A private dimension is a dimension created for an individual cube
2. A shared dimension is a dimension that can be used by multiple cubes
3. A virtual dimension is a logical dimension based on the columns from a physical dimension
4. The storage mode of a virtual dimension can be MOLAP, ROLAP or HOLAP

 

12. Which of the following is TRUE for Cube Storage Mode
1. MOLAP copies all of the data and all the aggregates to the analysis server in an optimized multidimensional format
2. ROLAP leaves the original data in the relational tables and uses separate set of relational tables to store the aggregates
3. In HOLAP, data remains in the relational tables, but aggregations are stored on the server in optimized multidimensional fomat
4. All the above

 
 

13. The following Storage Mode gives the best Query Performance
1. MOLAP
2. ROLAP
3. HOLAP

 
 

14. What is a Datamart
1. It is a subset of data warehouse and it supports a particular region, business unit or business function
2. It is a superset of data warehouse
3. It is a copy of data warehouse
4. None Of the above

 

15. Which of the following is false
1. In a star schema every dimension will have a primary key
2. In a star schema, a dimension table will have one or more parent tables
3. In a snow flake schema, dimension table will have one or more parent tables
4. In a star schema, hierarchies for the dimensions are stored in the dimensional table itself
5. In Snow Flake schema, hierarchies are broken into separate tables

 
 

16. Snowflaking means
1. Normalizing the data
2. Denormalizing the data
3. None of Above

 

17. Which of the following is false for Cubes
1. Cubes are multi-dimensional data representation
2. Cubes replicate data in the dimension and fact tables
3. Cubes do not require updating when the data warehouse data is updated
4. Cubes provide an easy-to-use mechanism for querying data with quick and uniform response times

 

18. The methods of processing the cubes
1. Incremental Update
2. Refresh Data
3. Process (Rebuild) Data
4. All the Above

 

19. Which of the following is false
1. Cube contains one or more Partitions
2. Virtual Cubes retrieve information across multiple cubes
3. Every Partition in a Cube should have the same storage mode
4. All the above

 

20. The Process by which data from transaction system or flat files is loaded in the datawarehouse schema is
1. Extraction
2. Transformation
3. Loading
4. All the above

 

21. During ETL load we generally have
1. Unsorted data for Aggregation
2. Sorted data for Aggregation
3. Does not matter if we use Sorted or Unsorted data for Aggregation

 
 

 

22. Sequence of jobs to load data in to warehouse
1. First load data into fact tables then dimension tables, then Aggregates if any
2. First load data into dimension tables, then fact tables, then Aggregates if any
3. First Aggregates then load data into dimension tables, then fact tables
4. Does not matter if we load either of fact, dimensions, or aggregates

 

23. Which of the following is false for Surrogate Keys
1. These keys are maintained within the data warehouse
2. These keys are taken from the source data
3. This uniquely identifies each entity in the dimension table regardless of its source key
4. All the above

 

24. The following is the characteristic(s) of Aggregations
1. Aggregations are precalculated summaries of data
2. Aggregations are stored in the multidimensional structure in cells at coordinates specified by the dimensions
3. Results in the fastest possible response time
4. All the above

 
 

25. The Data Analysis Tools  that can  be used to analyze data that is stored in  data warehouse
1. OLAP Manager
2. Microsoft Excel 2000
3. Microsoft English Query
4. All the above

 
 

26. Solution for managing Slowly Changing Dimension in which history of data is tracked accurately
1. Type 1: Overwrite the dimension record
2. Type 2: Write another dimension record
3. Type 3: Updating the dimension record and moving old value to a separate attribute
4. None of the above

 
 

27. Which of the following method is used to view the data at different levels of granularity
1. Drill Down
2. Drill Up
3. Drill Across
4. Drill Through
5. All the above

 

28. Drill Across generally uses the following join to generate report
1. Self Join
2. Inner Join
3. Outer Join

 

29. What is Data Mining
1. It is a process which removes the history data in the data warehouse
2. It is a process which removes the current data in the data warehouse
3. It is a process that looks at the data in the cube and searches for patterns
4. None of the above

 

30. In general data in Data Warehouse is
1. Normalized
2. Denormalized
3. None of the Above