ROW_NUMBER() is typically used for which purpose in SQL queries?

• A. Creating materialized views
• B. Pagination and row ordering
• C. Data type conversion
• D. Conflict resolution in join operations

Answer: (B)

ROW_NUMBER() is a window function that assigns a consecutive number to each row in a result set based on an order you specify. This ordered numbering is exactly what you need when you want to control which rows appear in a page of results, i.e., pagination, because you can pick a range of row numbers to return (for example, rows 11 through 20). It’s also useful for stable, deterministic ordering within partitions of data if you group by some column and restart numbering for each group.

This isn’t about creating materialized views, which store precomputed results, nor about converting data types, and it isn’t a tool for resolving conflicts in joins. Those tasks are handled by other features or functions. For example, you’d use ROW_NUMBER() to generate a page of results by numbering rows and then filtering by that number, or to assign a rank within each partition for deduplication or ordered processing.