A data warehouse may contain data at the first level of detail and summarized data. Which statement describes this capability?

A data warehouse may contain data at the first level of detail and summarized data. Which statement describes this capability?

• A. Detail data only
• B. Summarized data only
• C. Details and summarized data
• D. No data at different levels of detail

Answer: (C)

A data warehouse is designed to store data at multiple levels of detail, enabling both detailed analysis and fast, high-level summaries. This capability supports drill-down into the finest transactions and roll-up to aggregated figures for quicker insights, often through separate aggregate tables or materialized views alongside the detailed fact data. In practice, you might keep granular facts for precise analysis and also maintain summarized data at various aggregation levels (by day, by product, by region, etc.) to speed queries and reporting. So the statement that best describes this capability is that it includes both details and summarized data. The other options imply restricting to only one level of detail or denying the existence of multiple levels, which contradicts common data warehousing needs and OLAP usage.

A data warehouse is designed to store data at multiple levels of detail, enabling both detailed analysis and fast, high-level summaries. This capability supports drill-down into the finest transactions and roll-up to aggregated figures for quicker insights, often through separate aggregate tables or materialized views alongside the detailed fact data. In practice, you might keep granular facts for precise analysis and also maintain summarized data at various aggregation levels (by day, by product, by region, etc.) to speed queries and reporting.

So the statement that best describes this capability is that it includes both details and summarized data. The other options imply restricting to only one level of detail or denying the existence of multiple levels, which contradicts common data warehousing needs and OLAP usage.