Do you know that inside PostgreSQL, we have some kind of caching mechanism? For example, if you want to run a query that is very expensive, instead of running the query every time, you can use materialized views to cache the results. This way, it won’t run the expensive query repeatedly; instead, it will show the cached result. When you think you want to update the materialized view's data, you can use REFRESH MATERIALIZED VIEW . Then it will recalculate the query and save the results. This is useful for improving performance and loading the page faster.