Is it possible to create a caching mechanism at the database level?

Yes, caching mechanisms at the database level are possible and often used to improve performance. For example, many DBMSs support internal query or result caches, and external caching layers like Redis or Memcached can be used alongside the database.

Additionally, technologies such as Materialized Views store the results of complex queries and are updated on a schedule or when data changes, which can also be considered a form of caching at the database level.

An example of using a Materialized View in PostgreSQL:

CREATE MATERIALIZED VIEW recent_orders AS
SELECT * FROM orders WHERE order_date > now() - interval '1 day';

-- Refreshing the view
REFRESH MATERIALIZED VIEW recent_orders;