Which statement best describes a data warehouse according to classic definitions (subject-oriented, integrated, time-variant, non-volatile)?
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ACan be updated directly by end users.
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BContains numerous, inconsistent naming conventions and formats.
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COrganized around important subject areas.
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DContains only current data.
Answer
Correct Answer: Organized around important subject areas.
Explanation
Introduction / Context:Bill Inmon and Ralph Kimball describe a data warehouse as subject-oriented, integrated, time-variant, and non-volatile. Recognizing these traits distinguishes warehouses from OLTP systems.
Given Data / Assumptions:
- Warehouse content is curated for analysis by subject (e.g., sales, customer, product).
- Integration harmonizes naming, codes, and formats across sources.
- Warehouses store historical data and are not directly updated by end users.
Concept / Approach:“Subject-oriented” means schemas and marts are organized around business topics, not application transactions. “Integrated” means consistent naming and data definitions. “Time-variant” retains history; “non-volatile” avoids random end-user updates.
Step-by-Step Solution:
Check each option against the four traits.Only “organized around important subject areas” directly matches the “subject-oriented” trait.Eliminate options contradicting integration, history, and non-volatility.Verification / Alternative check:Warehousing literature consistently emphasizes subject areas and conformed dimensions for cross-process analysis.
Why Other Options Are Wrong:End-user updates: Violates non-volatility. Inconsistent naming: Violates integration. Only current data: Violates time-variance.
Common Pitfalls:Designing by source system rather than business subject, which hinders cross-functional analytics.
Final Answer:Organized around important subject areas.