What is the difference between a normal view and a materialized view?

A normal (or virtual) view is a stored SELECT statement that is executed each time the view is queried. It does not store data physically; it simply presents data from underlying tables, so it always reflects the latest data but can be slower for complex queries. A materialized view, on the other hand, stores the result set physically on disk. It is refreshed periodically (manually or automatically) and can be indexed, making query performance much faster for read‑heavy workloads. However, because it is not updated in real time, it may contain stale data between refreshes. Use normal views for simple, up‑to‑date reporting and materialized views when you need high performance for large, complex aggregations and can tolerate occasional staleness.