Use Views as Security Mechanisms

Data in an underlying table that is not included in the view is hidden from users who are authorized to access the view but not the underlying table.

Permission to access the subset of data in a view must be explicitly granted or revoked, regardless of the permissions in force on the view’s underlying tables.

For example, you may not want some users to access the columns that have to do with money and sales in the titles table. You can create a view of the titles table that omits those columns, and then give all users permission on the view, and give only the Sales Department permission on the table. For example:

revoke all on titles to public 
grant all on bookview to public 
grant all on titles to sales 

See, Managing User Permissions, in the Security Administration Guide.