What is Materialized View?

Unlike regular views that execute their query each time they are accessed, materialized views store query results physically on disk. This dramatically speeds up complex aggregations, joins, and analytical queries. The trade-off is data freshness — materialized views must be refreshed (manually or on schedule) to reflect underlying table changes. PostgreSQL supports REFRESH MATERIALIZED VIEW with a CONCURRENTLY option for zero-downtime refreshes. They are invaluable for dashboards, reports, and read-heavy workloads where slight data staleness is acceptable.