21.5. 默认角色
=====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 表 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.
表 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;