Data warehousing Flashcards
What is a data warehouse?
A. A storage area for operational data
B. A database optimized for transactional processing
C. A repository for historical and current data used for reporting and analysis
D. A file system for storing large amounts of unstructured data
C
Which of the following is a characteristic of a data warehouse?
A. Real-time data updates
B. Transaction processing
C. Subject-oriented
D. Unstructured data storage
C
What is ETL in the context of data warehousing?
A. Extract, Transform, Load
B. Encrypt, Transfer, Load
C. Extract, Test, Log
D. Extract, Track, Learn
A
What is the purpose of OLAP in a data warehouse?
A. Online Link Analysis Processing
B. Online Analytical Processing
C. Online Automated Processing
D. Online Logical Access Processing
B
Which schema is optimized for data warehouse query performance?
A. Star schema
B. Snowflake schema
C. ER diagram
D. Hierarchical schema
A
In data warehousing, a fact table consists of
A. Primary keys
B. Descriptive attributes
C. Dimension keys and measures
D. Foreign keys
C
Which process involves combining data from multiple sources into a single, coherent data store?
A. Data cleaning
B. Data integration
C. Data staging
D. Data extraction
B
What is the purpose of a data mart?
A. To store detailed data for long-term analysis
B. To store data for operational purposes
C. To store summarized data for a specific group or department
D. To store unstructured data
C
Which of the following is a key consideration when designing a data warehouse?
A. Minimizing data redundancy
B. Maximizing data normalization
C. Ensuring real-time data updates
D. Incorporating unstructured data
A
Which component is responsible for providing query results to users in a data warehouse?
A. ETL Server
B. Data Warehouse Server
C. OLAP Server
D. Metadata Server
C
What does the term “dimension” refer to in a data warehouse?
A. It refers to the measurement of data.
B. It represents a collection of facts.
C. It provides context to measures and attributes.
D. It represents the primary key in a fact table.
C
Which data warehouse architecture involves integrating data from multiple sources before loading it into the warehouse?
A. Federated
B. Centralized
C. Hub-and-Spoke
D. Data Mart
B
What is the purpose of metadata in a data warehouse?
A. To store primary data
B. To manage data security
C. To provide information about data characteristics
D. To encrypt data
C
Which process involves identifying and correcting errors or inconsistencies in data?
A. Data integration
B. Data cleansing
C. Data aggregation
D. Data mining
B
What is the primary function of a data warehouse manager?
A. Designing user interfaces for data access
B. Managing and maintaining data quality
C. Writing complex SQL queries
D. Developing machine learning algorithms
B
What role does a star schema play in data warehousing?
A. It provides a visual representation of data relationships.
B. It facilitates data encryption in the warehouse.
C. It optimizes query performance by denormalizing tables.
D. It represents the relationships between dimensions.
C
Which technique is used to summarize and aggregate data in a data warehouse?
A. Data mining
B. Roll-up
C. Data cleaning
D. Data staging
B
What is the role of surrogate keys in a data warehouse?
A. They act as primary keys in the source system.
B. They are used for indexing data in OLAP.
C. They represent the actual business keys in a dimension table.
D. They uniquely identify rows in a table.
D
What is the purpose of a slowly changing dimension (SCD. in a data warehouse?
A. To track changes in data over time
B. To store data without any changes
C. To eliminate redundant data
D. To improve data loading speed
A
Which technology is commonly used for data extraction in a data warehouse environment?
A. JDBC (Java Database Connectivity)
B. HTML (Hypertext Markup Language)
C. XML (Extensible Markup Language)
D. API (Application Programming Interface)
A
What is the primary goal of data warehousing?
A. To ensure data security
B. To facilitate data mining
C. To support decision-making processes
D. To replace transactional databases
C
Which process involves transforming data into a consistent format for analysis in a data warehouse?
A. Data profiling
B. Data normalization
C. Data summarization
D. Data scrubbing
D