Unit 3: Data Warehouse - Practice Quiz

INT323 — Database Essentials Toward Informatica 50 Questions
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1 Who is widely recognized as the 'Father of Data Warehousing'?

A. E.F. Codd
B. Peter Chen
C. Bill Inmon
D. Ralph Kimball

2 A Data Warehouse is defined as a subject-oriented, integrated, time-variant, and ____ collection of data.

A. Virtual
B. Volatile
C. Non-volatile
D. Transient

3 Which characteristic of a Data Warehouse implies that data is organized around major entities such as customer, product, and sales?

A. Time-variant
B. Subject-oriented
C. Non-volatile
D. Integrated

4 In the context of Data Warehousing, what does 'Integrated' mean?

A. Data is encrypted for security
B. Data is stored in a single file
C. Data is accessible via the web
D. Data is collected from various sources and standardized

5 What is the primary purpose of the 'Staging Area' in Data Warehouse architecture?

A. To store data permanently
B. To clean and transform data before loading it into the warehouse
C. To provide query access to end-users
D. To store meta-data only

6 Which type of data represents the 'Time-variant' nature of a Data Warehouse?

A. Historical data spanning a specific period
B. Future predictive data
C. Current real-time data only
D. Temporary session data

7 What is a 'Data Mart'?

A. A subset of a data warehouse focused on a specific department or function
B. A backup storage device
C. A complete enterprise-wide data warehouse
D. A tool for data mining

8 Which architecture approach advocates building the Enterprise Data Warehouse (EDW) first and then creating Data Marts?

A. Bottom-up Approach
B. Spiral Approach
C. Agile Approach
D. Top-down Approach

9 The 'Bottom-up' approach to Data Warehousing, which starts with Data Marts, is associated with:

A. Larry Ellison
B. Ralph Kimball
C. Edgar Codd
D. Bill Inmon

10 What does OLAP stand for?

A. Online Analytical Processing
B. Overlay Analytical Platform
C. Offline Analysis Protocol
D. Online Advanced Programming

11 Which table in a schema contains the quantitative data (numbers/metrics) for analysis?

A. Meta Table
B. Fact Table
C. Dimension Table
D. Index Table

12 Which table contains descriptive attributes used for query filtering and labeling?

A. Dimension Table
B. Measure Table
C. Fact Table
D. Summary Table

13 In a Star Schema, how are tables arranged?

A. A central dimension table connected to multiple fact tables
B. Multiple fact tables sharing dimension tables
C. A central fact table connected to multiple dimension tables
D. Normalized tables linked in a chain

14 What distinguishes a Snowflake Schema from a Star Schema?

A. It uses only one table
B. It does not support SQL
C. The Fact table is normalized
D. The Dimension tables are normalized

15 A 'Fact Constellation' schema is also known as:

A. Galaxy Schema
B. Bus Schema
C. Snowflake Schema
D. Star Schema

16 What is 'Meta-data' in the context of a Data Warehouse?

A. The actual business data
B. Backup data
C. Data about data
D. Deleted data

17 Which OLAP operation allows moving from summary data to detailed data?

A. Roll-up
B. Drill-down
C. Slice
D. Dice

18 Which OLAP operation performs aggregation on a data cube (e.g., climbing up the hierarchy)?

A. Pivot
B. Roll-up
C. Slice
D. Drill-down

19 Selecting a single value for one dimension to create a subset of the cube is called:

A. Pivoting
B. Dicing
C. Slicing
D. Drilling

20 Which type of OLAP stores data in a multidimensional array-based storage engine?

A. DOLAP
B. ROLAP
C. HOLAP
D. MOLAP

21 ROLAP stands for:

A. Real-time Online Analytical Processing
B. Relational Online Analytical Processing
C. Remote Online Analytical Processing
D. Rapid Online Analytical Processing

22 HOLAP attempts to combine the best features of:

A. ROLAP and MOLAP
B. Star and Snowflake Schemas
C. OLTP and OLAP
D. Data Mining and Data Warehousing

23 Which of the following is NOT a typical application of a Data Warehouse?

A. Decision Support Systems (DSS)
B. Transaction Processing (OLTP)
C. Reporting and Forecasting
D. Trend Analysis

24 What is the acronym ETL short for?

A. Extract, Test, Lock
B. Extract, Transform, Load
C. Evaluate, Transfer, Load
D. Enter, Transform, List

25 In the context of ETL, 'Transformation' includes:

A. Giving users read access
B. Cleaning, filtering, and aggregating data
C. Installing database software
D. Backing up data to tape

26 What is an ODS in Data Warehousing architecture?

A. Online Decision System
B. Object Data Source
C. Operational Data Store
D. Offline Data Storage

27 Which utility is primarily used to refresh a data warehouse with new data?

A. Security Manager
B. Data Loading Utility
C. Index Creator
D. Query Manager

28 What is the 'Grain' of a fact table?

A. The size of the table on disk
B. The number of columns
C. The level of detail represented by a single row
D. The type of database used

29 Which schema results in the highest performance for queries due to fewer joins?

A. Star Schema
B. Hierarchical Schema
C. Snowflake Schema
D. Normalized Schema

30 What type of metadata allows tools to understand how to navigate the data (e.g., mapping source to target)?

A. Social Metadata
B. Technical/Operational Metadata
C. Administrative Metadata
D. Business Metadata

31 A 'Dependent Data Mart' is sourced from:

A. Directly from operational systems
B. External flat files only
C. The Enterprise Data Warehouse
D. User input

32 An 'Independent Data Mart' is sourced from:

A. The backup server
B. The Enterprise Data Warehouse
C. Directly from operational source systems
D. Another Data Mart

33 Which of the following is a security concern in Data Warehousing?

A. Keeping data volatile
B. Controlling access to sensitive aggregated data
C. Ensuring data is not time-variant
D. Reducing data redundancy

34 What is the purpose of a 'Surrogate Key' in a dimension table?

A. To link to the internet
B. To encrypt the data
C. To replace the natural primary key with an internal system integer
D. To store the date

35 In the Three-Tier Data Warehouse Architecture, what constitutes the bottom tier?

A. Front-end tools
B. Data Warehouse Database Server
C. OLAP Server
D. Web Interface

36 In the Three-Tier Data Warehouse Architecture, what is the middle tier?

A. Reporting Tools
B. OLAP Server
C. Relational Database
D. Data Mining Tools

37 Which of the following is a benefit of Data Warehousing?

A. Increases transactional processing speed
B. Replaces the need for backups
C. Enhances business intelligence and decision making
D. Reduces storage requirements

38 What is 'Data Scrubbing'?

A. Deleting data permanently
B. Merging data marts
C. Cleaning data to remove inconsistencies and errors
D. Compressing data

39 The operation of rotating the data axes in an OLAP cube to view data from different perspectives is called:

A. Dice
B. Slice
C. Pivot
D. Drill-up

40 Which backup strategy involves copying the entire data warehouse?

A. Full Backup
B. Partial Backup
C. Differential Backup
D. Incremental Backup

41 Why is backup crucial for a Data Warehouse despite it being a read-mostly system?

A. To increase query speed
B. Data is volatile
C. To allow write operations
D. To recover from hardware failure or data corruption

42 A 'Virtual Data Warehouse' is:

A. A simulation of a database
B. A cloud-based physical storage
C. An empty database
D. A set of views over operational databases

43 Which tool category allows end-users to create reports and graphs from the Data Warehouse?

A. Operating Systems
B. Data Access/Reporting Tools
C. ETL Tools
D. Database Management Systems

44 In a Fact Table, a 'Measure' that can be summed across all dimensions is called:

A. Non-additive
B. Additive
C. Semi-additive
D. Subtractive

45 A 'Semi-additive' measure is one that:

A. Cannot be summed at all
B. Can be summed across all dimensions
C. Can be summed across some dimensions but not others
D. Is always text

46 Which utility is used to monitor the performance of the Data Warehouse?

A. Warehouse Manager
B. Query Manager
C. Load Manager
D. System/Performance Monitor

47 The define-measure-analyze-improve-control cycle is often supported by data from:

A. Text Editors
B. Data Warehouses
C. Web Browsers
D. Network Routers

48 What is the specific challenge of 'Data Marting' when done independently?

A. It is too slow
B. It requires too much storage
C. It is too expensive
D. It creates inconsistent 'islands of information'

49 Which of the following best describes 'Business Metadata'?

A. Log files of server activity
B. Physical database schema details
C. Programming code for ETL
D. Terms, definitions, and ownership info for business users

50 In the context of Informatica and DW, what is a 'Repository'?

A. The hardware where data is stored
B. The operational source system
C. A central database storing metadata and transformation rules
D. The final report generated