Hello team, thanks for reaching out us, it will be a pleasure to help you on this ask.
That's a great catch to run through a materialized, view and regarding the question: If any record of underlying table is inserted, updated or deleted, the only respective materialized view refreshed? Or It should run all the Materialized views in the pipeline?
The answer is yes , In Delta Live Tables, when a record of the underlying table is inserted, updated, or deleted, only the respective materialized view is refreshed. This is because Delta Live Tables are designed to incrementally compute changes from the base tables, thus ensuring that the materialized views are updated as the underlying data changes.
However, it's important to note that the Delta Live Tables runtime cannot detect changes in non-Delta data sources. In such cases, the table is still updated regularly but with a higher default trigger interval to prevent excessive re-computation from slowing down any incremental processing happening on compute.
For more details you can refer to the following docs:
[1] Materialized views: https://docs.databricks.com/en/sql/user/materialized-views.html
[2] Refreshing materialized views: https://www.databricks.com/glossary/materialized-views
