Projection access Grants

When you create a table and grant accesses to it (USAGE on schema and SELECT on table), you let the user access that table's data. Projections are related to the data placement on device (disk) and they are on the lower level, so you cannot access it. Please check out the documentation.

HP Vertica does not associate privileges directly with projections since they are the underlying storage construct. Privileges may only be granted on the logical storage containers: the tables and views.

https://my.vertica.com/docs/7.0.x/HTML/index.htm#Authoring/AdministratorsGuide/Security/DBUsersAndPr...