Public is the role used for unregistered users. By default, the public role has no permissions. Users cannot even view a list of databases that are accessible to users with only the Gamma role. It is not recommended that you provide any permissions to the Public role.
For quick reference, the following table describes each role, broken down by types of functions they can perform:
| Admin | Alpha | Gamma | SQL Lab | |
| Add or remove users | Yes | No | No | No |
| Create, remove, or modify data sources | Yes | Yes | No | No |
| View charts and dashboards | Yes | Yes | Yes, if data source access also available | No |
| Modify charts and dashboards | Yes | Yes | No | No |
| Create charts and dashboards | Yes | Yes | Yes, if data source access assigned and also available | No |
| SQL Lab access | Yes | No | No | Yes |