Hello @kranthi2 , I hope you're doing well.
It seems that this command won't work for MVs, as it expected table. When trying to run the following command, for example:
ALTER TABLE `catalog`.`schema`.`MV` ALTER COLUMN column_ SET MASK mask_func;
We get the following error:
[EXPECT_TABLE_NOT_VIEW.NO_ALTERNATIVE] 'ALTER TABLE ... ALTER COLUMN' expects a table but `catalog`.`schema`.`MV` is a view. SQLSTATE: 42809
[EXPECT_TABLE_NOT_VIEW.NO_ALTERNATIVE] 'ALTER TABLE ... ALTER COLUMN' expects a table but `catalog`.`schema`.`MV` is a view. SQLSTATE: 42809
Also, if you go to the table through Catalog, and follow the docs steps:
Doc.: https://docs.databricks.com/en/tables/row-and-column-filters.html#apply-a-column-mask
In a MV, you will face the following message:
To add or remove column mask for Materialized Views, use the CREATE OR REPLACE statement
Which indicates that, for now, this operation is not possible for MVs.
If you believe this feature of adding column mask to MVs through ALTER TABLE/VIEW would be beneficial, you could submit an idea in Databricks' Ideas Portal.
Best regards,
Lucas Rocha
Technical Solutions Engineer
