A masking policy cannot be set on a table if a materialized view already exists from that underlying table.

• A. True
• B. False
• C. Only in some cases
• D. Not related

Answer: (A)

Masking policies control how much of the data is revealed when a column is queried, and they are applied at query time as the data is returned to the user. A materialized view, however, stores a precomputed snapshot of data from the underlying table. If a masking policy were directly tied to the base table while a materialized view depends on that table, the MV could return data that was captured before the policy was applied or could bypass the policy entirely when users query through the MV. To avoid inconsistencies and potential data exposure, Snowflake restricts setting a masking policy on a table when a materialized view exists on that table. If you need masking, you would either drop or re-create the MV (or apply masking directly within the MV’s definition) so that all query paths reflect the intended masking.