Efficiently updating materialized views
Flexviews must be instructed about the calculations that it must perform on the data, and this can be done via the SQL_API or via (one for each materialized view).An SQL event called apply_views periodically applies these changes to the materialized views.
Because of this, materialized views must be frequently "refreshed" to bring them up-to-date.
By caching result set data into a real table, the data can be accessed much more quickly, but at the cost of some data being potentially out-of-date.
It is most useful in data warehousing scenarios, where frequent queries of the actual base tables can be extremely expensive.
Scylla’s materialized views feature, which has been introduced in 2.0 as an experimental feature, moves this complexity out of the application and into the servers.
With fewer round trips to the applications, this implementation is faster and more reliable.