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

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

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

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

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

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

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

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

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

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

A. Historical data spanning a specific period
B. Current real-time data only
C. Temporary session data
D. Future predictive 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 tool for data mining
D. A complete enterprise-wide data warehouse

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

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

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

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

10 What does OLAP stand for?

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

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

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

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

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

13 In a Star Schema, how are tables arranged?

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

14 What distinguishes a Snowflake Schema from a Star Schema?

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

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

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

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

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

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

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

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

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

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

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

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

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

21 ROLAP stands for:

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

22 HOLAP attempts to combine the best features of:

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

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

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

24 What is the acronym ETL short for?

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

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

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

26 What is an ODS in Data Warehousing architecture?

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

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

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

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

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

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

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

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

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

31 A 'Dependent Data Mart' is sourced from:

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

32 An 'Independent Data Mart' is sourced from:

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

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

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

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

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

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

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

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

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

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

A. Replaces the need for backups
B. Enhances business intelligence and decision making
C. Increases transactional processing speed
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. Pivot
B. Slice
C. Dice
D. Drill-up

40 Which backup strategy involves copying the entire data warehouse?

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

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

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

42 A 'Virtual Data Warehouse' is:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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