## 21.5. Default Roles

PostgreSQL provides a set of default roles which provide access to certain, commonly needed, privileged capabilities and information. Administrators can GRANT these roles to users and/or other roles in their environment, providing those users with access to the specified capabilities and information.

The default roles are described in Table 21.1. Note that the specific permissions for each of the default roles may change in the future as additional capabilities are added. Administrators should monitor the release notes for changes.

Table 21.1. Default Roles

Role | Allowed Access
--- | ---
pg_signal_backend | Send signals to other backends (eg: cancel query, terminate).

Administrators can grant access to these roles to users using the GRANT command:

    GRANT pg_signal_backend TO admin_user;