Q. In a star schema, what do the fact tables contain?
A.Dimension attributes
B.Aggregated data
C.Transactional data
D.Metadata
Solution
Fact tables in a star schema contain transactional data that can be analyzed, often including measures and foreign keys to dimension tables.
Correct Answer: C — Transactional data
Q. In a star schema, what do the fact tables represent?
A.Dimensions of the data
B.Aggregated data
C.Transactional data
D.Metadata
Solution
Fact tables in a star schema represent transactional data, containing measurable, quantitative data for analysis.
Correct Answer: C — Transactional data
Q. In the context of data warehousing, what does ETL stand for?
A.Extract, Transform, Load
B.Evaluate, Test, Launch
C.Execute, Transfer, Log
D.Extract, Transfer, Load
Solution
ETL stands for Extract, Transform, Load, which is the process of moving data from source systems into a data warehouse.
Correct Answer: A — Extract, Transform, Load
Q. What does the term 'data latency' refer to in a data warehouse?
A.The speed of data retrieval
B.The time delay between data generation and its availability for analysis
C.The amount of data stored
D.The frequency of data updates
Solution
Data latency refers to the time delay between when data is generated and when it becomes available for analysis in a data warehouse.
Correct Answer: B — The time delay between data generation and its availability for analysis
Q. What is a dimension table in a data warehouse?
A.A table that stores transactional data
B.A table that contains descriptive attributes
C.A table that holds metadata
D.A table that indexes data
Solution
Dimension tables contain descriptive attributes that provide context to the facts stored in the fact tables.
Correct Answer: B — A table that contains descriptive attributes
Q. What is a star schema in data warehousing?
A.A type of data normalization
B.A database design with a central fact table and dimension tables
C.A method for indexing data
D.A concurrency control mechanism
Solution
A star schema is a type of database design that consists of a central fact table surrounded by dimension tables, facilitating easier data retrieval.
Correct Answer: B — A database design with a central fact table and dimension tables
Q. What is the main advantage of using indexing in a data warehouse?
A.Increased data redundancy
B.Faster query performance
C.Simplified data modeling
D.Reduced storage requirements
Solution
Indexing improves query performance by allowing the database to find data more quickly, which is crucial in a data warehouse environment.
Correct Answer: B — Faster query performance
Q. What is the main purpose of data normalization in a data warehouse?
A.To reduce data redundancy
B.To improve query performance
C.To enhance data integrity
D.To simplify data retrieval
Solution
Data normalization aims to reduce data redundancy and improve data integrity, although it is less common in data warehousing compared to operational databases.
Correct Answer: A — To reduce data redundancy
Q. What is the primary function of OLAP in data warehousing?
A.To perform online transaction processing
B.To support complex queries and data analysis
C.To manage data integrity
D.To facilitate data entry
Solution
OLAP (Online Analytical Processing) is used in data warehousing to support complex queries and data analysis.
Correct Answer: B — To support complex queries and data analysis
Q. What is the primary purpose of a data warehouse?
A.To store operational data
B.To support business intelligence activities
C.To manage transaction processing
D.To perform real-time analytics
Solution
A data warehouse is designed to support business intelligence activities by consolidating data from various sources for analysis.
Correct Answer: B — To support business intelligence activities
Q. What is the purpose of data normalization in a data warehouse?
A.To reduce data redundancy
B.To improve query performance
C.To enhance data integrity
D.To simplify data retrieval
Solution
Normalization aims to reduce data redundancy and improve data integrity, although data warehouses often use denormalization for performance.
Correct Answer: A — To reduce data redundancy
Q. What is the purpose of ETL in data warehousing?
A.Extract, Transform, Load
B.Evaluate, Test, Launch
C.Execute, Transfer, Log
D.Enhance, Transfer, Load
Solution
ETL stands for Extract, Transform, Load, which is the process of moving data from source systems into a data warehouse.
Correct Answer: A — Extract, Transform, Load
Q. What is the role of a dimension table in a data warehouse?
A.To store transactional data
B.To provide context to fact data
C.To manage user access
D.To perform data cleansing
Solution
Dimension tables provide context to the fact data, allowing users to analyze the facts in relation to various attributes.
Correct Answer: B — To provide context to fact data
Q. What is the role of indexing in a data warehouse?
A.To ensure data integrity
B.To speed up query performance
C.To normalize data
D.To manage user access
Solution
Indexing in a data warehouse is used to speed up query performance by allowing faster data retrieval.
Correct Answer: B — To speed up query performance
Q. Which concurrency control method is commonly used in data warehousing?
A.Pessimistic locking
B.Optimistic locking
C.Two-phase locking
D.Timestamp ordering
Solution
Optimistic locking is often used in data warehousing environments where read operations are more frequent than write operations.
Correct Answer: B — Optimistic locking
Q. Which of the following best describes a data mart?
A.A large-scale data warehouse
B.A subset of a data warehouse focused on a specific business area
C.A type of database management system
D.A method for data extraction
Solution
A data mart is a smaller, more focused version of a data warehouse, designed to serve the needs of a specific business area.
Correct Answer: B — A subset of a data warehouse focused on a specific business area
Q. Which of the following best describes data mart?
A.A large-scale data warehouse
B.A subset of a data warehouse
C.A type of operational database
D.A data processing tool
Solution
A data mart is a subset of a data warehouse, often focused on a specific business line or team.
Correct Answer: B — A subset of a data warehouse
Q. Which of the following best describes ETL in the context of data warehousing?
A.Extract, Transform, Load
B.Evaluate, Test, Launch
C.Execute, Transfer, Log
D.Extract, Transfer, Load
Solution
ETL stands for Extract, Transform, Load, which is the process of moving data from source systems into a data warehouse.
Correct Answer: A — Extract, Transform, Load
Q. Which of the following is a characteristic of a data warehouse?
A.Normalized data structure
B.Real-time data processing
C.Historical data storage
D.Transactional data management
Solution
Data warehouses are characterized by their ability to store historical data for analysis, unlike operational databases which focus on current transactions.
Correct Answer: C — Historical data storage
Q. Which of the following is a common method for ensuring data consistency in a data warehouse?
A.Data replication
B.Data normalization
C.Data denormalization
D.Data partitioning
Solution
Data replication is a common method used to ensure data consistency across different systems in a data warehouse.
Correct Answer: A — Data replication
Q. Which of the following is NOT a benefit of data warehousing?
A.Improved data quality
B.Enhanced data analysis capabilities
C.Increased transaction speed
D.Consolidated data from multiple sources
Solution
Data warehousing focuses on analytical processing rather than transaction speed, which is a characteristic of operational databases.
Correct Answer: C — Increased transaction speed
Q. Which of the following is NOT a type of data warehouse architecture?
A.Single-tier architecture
B.Two-tier architecture
C.Three-tier architecture
D.Multi-dimensional architecture
Solution
Multi-dimensional architecture is not a recognized type of data warehouse architecture; the common types are single-tier, two-tier, and three-tier.
Correct Answer: D — Multi-dimensional architecture
Q. Which of the following is NOT a typical use case for a data warehouse?
A.Business intelligence reporting
B.Data mining
C.Real-time transaction processing
D.Historical data analysis
Solution
Data warehouses are not typically used for real-time transaction processing, which is better suited for operational databases.
Correct Answer: C — Real-time transaction processing
