A Data Set is usually a which type of table derived from a relational database or data warehouse?

• A. De-normalized
• B. Normalized
• C. Indexed
• D. Partitioned

Answer: (A)

A dataset prepared for analysis is typically denormalized. In relational databases, normalization reduces data redundancy by splitting information into separate related tables. For data mining and reporting, a flat, wide table that combines related fields makes it much faster and easier to analyze, because you can access all the needed attributes without performing many joins. This denormalized structure often arises in data warehouses in a star-like layout, where a fact table is joined with dimension attributes to produce a single, analysis-ready dataset. Normalized tables slow down exploratory queries due to multiple joins, indexing is a performance feature rather than the dataset’s form, and partitioning concerns storage organization rather than the dataset’s shape. So the common practice is to denormalize to create a practical, analysis-friendly dataset.