The DBC.AccessRights table stores the field ID of a column on which an INSERT, REFERENCES, SELECT, or UPDATE privilege has been granted. The column type is SMALLINT and cannot be null. If the privilege defined by the row is not at the column level then the value of the column is set to zero.
Column-level privileges are held implicitly by the owners of a table. As is true for implicit privileges, a row is not inserted into DBC.AccessRights for implicit column-level privileges.
Rows are also not generated in DBC.AccessRights for individual columns when the INSERT, REFERENCES, SELECT, or UPDATE privileges are granted at the table level.
Rows are generated in DBC.AccessRights only for privileges granted by a GRANT statement at the column level when the grantee does not have the privilege at the table level. The only exception is the case of a user or database that has a privilege at table level but without GRANT authority and who then is granted the same privilege on an individual column of the same table with grant authority.