Materialized views speed up which kind of operations?

• A. Expensive aggregation, projection, and selection operations, especially those that run frequently and on large data sets
• B. Simple single-row lookups
• C. Joins only
• D. Real-time streaming operations

Answer: (A)

Materialized views precompute and store the results of a query so subsequent executions can read the prepared data instead of redoing the heavy work. This approach speeds up expensive operations like aggregations, projections, and selections, especially when those queries run frequently on large data sets, because the costly computation has already been done and kept ready for quick retrieval. The benefit is most apparent when the same complex query is executed many times, making the runtime much shorter than re-scanning and re-aggregating the base tables. Simple single-row lookups are already fast from the base tables, so the gain from a materialized view is typically smaller there. While a materialized view can include joined data, it isn’t limited to joins, and it isn’t primarily designed for real-time streaming, since maintaining freshness of the precomputed data introduces a refresh overhead rather than true, continuous streaming.