v.23.11Improvement
Engine Merge Filters Records by Row Policies
EngineMergefilters the records according to the row policies of the underlying tables, so you don't have to create another row policy on aMergetable. #50209 (Ilya Golshtein).
Why it matters
This feature simplifies access control by ensuring that row-level security policies defined on individual tables are respected when querying aMerge table that combines those tables. It saves users from duplicating row policies, reducing administrative overhead and potential errors.How to use it
No additional configuration is needed. When you query aMerge table, the row policies defined on its underlying tables are applied automatically, filtering the data according to those policies.