A database role can have a number of attributes that define its privileges and interact with the client authentication system.
Only roles that have the
LOGIN attribute can be used as the initial role name for a database connection. A role with the
LOGIN attribute can be considered the same as a “database user”. To create a role with login privilege, use either:
nameLOGIN; CREATE USER
CREATE USER is equivalent to
CREATE ROLE except that
CREATE USER includes
LOGIN by default, while
CREATE ROLE does not.)
A database superuser bypasses all permission checks, except the right to log in. This is a dangerous privilege and should not be used carelessly; it is best to do most of your work as a role that is not a superuser. To create a new database superuser, use
CREATE ROLE . You must do this as a role that is already a superuser.
A role must be explicitly given permission to create databases (except for superusers, since those bypass all permission checks). To create such a role, use
CREATE ROLE .
A role must be explicitly given permission to create more roles (except for superusers, since those bypass all permission checks). To create such a role, use
CREATE ROLE . A role with
CREATEROLE privilege can alter and drop roles which have been granted to the
CREATEROLE user with the
ADMIN option. Such a grant occurs automatically when a
CREATEROLE user that is not a superuser creates a new role, so that by default, a
CREATEROLE user can alter and drop the roles which they have created. Altering a role includes most changes that can be made using
ALTER ROLE, including, for example, changing passwords. It also includes modifications to a role that can be made using the
SECURITY LABEL commands.
CREATEROLE does not convey the ability to create
SUPERUSER roles, nor does it convey any power over
SUPERUSER roles that already exist. Furthermore,
CREATEROLE does not convey the power to create
REPLICATION users, nor the ability to grant or revoke the
REPLICATION privilege, nor the ability to modify the role properties of such users. However, it does allow
ALTER ROLE ... SET and
ALTER ROLE ... RENAME to be used on
REPLICATION roles, as well as the use of
COMMENT ON ROLE,
SECURITY LABEL ON ROLE, and
DROP ROLE. Finally,
CREATEROLE does not confer the ability to grant or revoke the
A role must explicitly be given permission to initiate streaming replication (except for superusers, since those bypass all permission checks). A role used for streaming replication must have
LOGIN permission as well. To create such a role, use
CREATE ROLE .
name REPLICATION LOGIN
A password is only significant if the client authentication method requires the user to supply a password when connecting to the database. The
md5 authentication methods make use of passwords. Database passwords are separate from operating system passwords. Specify a password upon role creation with
CREATE ROLE .
name PASSWORD '
A role inherits the privileges of roles it is a member of, by default. However, to create a role which does not inherit privileges by default, use
CREATE ROLE . Alternatively, inheritance can be overridden for individual grants by using
WITH INHERIT TRUE or
WITH INHERIT FALSE.
A role must be explicitly given permission to bypass every row-level security (RLS) policy (except for superusers, since those bypass all permission checks). To create such a role, use
CREATE ROLE as a superuser.
Connection limit can specify how many concurrent connections a role can make. -1 (the default) means no limit. Specify connection limit upon role creation with
CREATE ROLE .
name CONNECTION LIMIT '
A role's attributes can be modified after creation with
ALTER ROLE. See the reference pages for the CREATE ROLE and ALTER ROLE commands for details.
A role can also have role-specific defaults for many of the run-time configuration settings described in Chapter 20. For example, if for some reason you want to disable index scans (hint: not a good idea) anytime you connect, you can use:
ALTER ROLE myname SET enable_indexscan TO off;
This will save the setting (but not set it immediately). In subsequent connections by this role it will appear as though
SET enable_indexscan TO off had been executed just before the session started. You can still alter this setting during the session; it will only be the default. To remove a role-specific default setting, use
ALTER ROLE . Note that role-specific defaults attached to roles without
LOGIN privilege are fairly useless, since they will never be invoked.
When a non-superuser creates a role using the
CREATEROLE privilege, the created role is automatically granted back to the creating user, just as if the bootstrap superuser had executed the command
GRANT created_user TO creating_user WITH ADMIN TRUE, SET FALSE, INHERIT FALSE. Since a
CREATEROLE user can only exercise special privileges with regard to an existing role if they have
ADMIN OPTION on it, this grant is just sufficient to allow a
CREATEROLE user to administer the roles they created. However, because it is created with
INHERIT FALSE, SET FALSE, the
CREATEROLE user doesn't inherit the privileges of the created role, nor can it access the privileges of that role using
SET ROLE. However, since any user who has
ADMIN OPTION on a role can grant membership in that role to any other user, the
CREATEROLE user can gain access to the created role by simply granting that role back to themselves with the
SET options. Thus, the fact that privileges are not inherited by default nor is
SET ROLE granted by default is a safeguard against accidents, not a security feature. Also note that, because this automatic grant is granted by the bootstrap user, it cannot be removed or changed by the
CREATEROLE user; however, any superuser could revoke it, modify it, and/or issue additional such grants to other
CREATEROLE users. Whichever
CREATEROLE users have
ADMIN OPTION on a role at any given time can administer it.