NAME
CREATE ROLE - define a new database role
SYNOPSIS
CREATE ROLE name [ [ WITH ] option [ ... ] ]
where option can be:
SUPERUSER | NOSUPERUSER
| CREATEDB | NOCREATEDB
| CREATEROLE | NOCREATEROLE
| CREATEUSER | NOCREATEUSER
| INHERIT | NOINHERIT
| LOGIN | NOLOGIN
| CONNECTION LIMIT connlimit
| [ ENCRYPTED | UNENCRYPTED ] PASSWORD ’password’
| VALID UNTIL ’timestamp’
| IN ROLE rolename [, ...]
| IN GROUP rolename [, ...]
| ROLE rolename [, ...]
| ADMIN rolename [, ...]
| USER rolename [, ...]
| SYSID uid
DESCRIPTION
CREATE ROLE adds a new role to a PostgreSQL database cluster. A role is
an entity that can own database objects and have database privileges; a
role can be considered a ‘‘user’’, a ‘‘group’’, or both depending on
how it is used. Refer to in the documentation and in the documentation
for information about managing users and authentication. You must have
CREATEROLE privilege or be a database superuser to use this command.
Note that roles are defined at the database cluster level, and so are
valid in all databases in the cluster.
PARAMETERS
name The name of the new role.
SUPERUSER
NOSUPERUSER
These clauses determine whether the new role is a ‘‘superuser’’,
who can override all access restrictions within the database.
Superuser status is dangerous and should be used only when
really needed. You must yourself be a superuser to create a new
superuser. If not specified, NOSUPERUSER is the default.
CREATEDB
NOCREATEDB
These clauses define a role’s ability to create databases. If
CREATEDB is specified, the role being defined will be allowed to
create new databases. Specifying NOCREATEDB will deny a role the
ability to create databases. If not specified, NOCREATEDB is the
default.
CREATEROLE
NOCREATEROLE
These clauses determine whether a role will be permitted to
create new roles (that is, execute CREATE ROLE). A role with
CREATEROLE privilege can also alter and drop other roles. If
not specified, NOCREATEROLE is the default.
CREATEUSER
NOCREATEUSER
These clauses are an obsolete, but still accepted, spelling of
SUPERUSER and NOSUPERUSER. Note that they are not equivalent to
CREATEROLE as one might naively expect!
INHERIT
NOINHERIT
These clauses determine whether a role ‘‘inherits’’ the
privileges of roles it is a member of. A role with the INHERIT
attribute can automatically use whatever database privileges
have been granted to all roles it is directly or indirectly a
member of. Without INHERIT, membership in another role only
grants the ability to SET ROLE to that other role; the
privileges of the other role are only available after having
done so. If not specified, INHERIT is the default.
LOGIN
NOLOGIN
These clauses determine whether a role is allowed to log in;
that is, whether the role can be given as the initial session
authorization name during client connection. A role having the
LOGIN attribute can be thought of as a user. Roles without this
attribute are useful for managing database privileges, but are
not users in the usual sense of the word. If not specified,
NOLOGIN is the default, except when CREATE ROLE is invoked
through its alternative spelling CREATE USER.
CONNECTION LIMIT connlimit
If role can log in, this specifies how many concurrent
connections the role can make. -1 (the default) means no limit.
PASSWORD password
Sets the role’s password. (A password is only of use for roles
having the LOGIN attribute, but you can nonetheless define one
for roles without it.) If you do not plan to use password
authentication you can omit this option. If no password is
specified, the password will be set to null and password
authentication will always fail for that user. A null password
can optionally be written explicitly as PASSWORD NULL.
ENCRYPTED
UNENCRYPTED
These key words control whether the password is stored encrypted
in the system catalogs. (If neither is specified, the default
behavior is determined by the configuration parameter
password_encryption.) If the presented password string is
already in MD5-encrypted format, then it is stored encrypted as-
is, regardless of whether ENCRYPTED or UNENCRYPTED is specified
(since the system cannot decrypt the specified encrypted
password string). This allows reloading of encrypted passwords
during dump/restore.
Note that older clients might lack support for the MD5
authentication mechanism that is needed to work with passwords
that are stored encrypted.
VALID UNTIL ’timestamp’
The VALID UNTIL clause sets a date and time after which the
role’s password is no longer valid. If this clause is omitted
the password will be valid for all time.
IN ROLE rolename
The IN ROLE clause lists one or more existing roles to which the
new role will be immediately added as a new member. (Note that
there is no option to add the new role as an administrator; use
a separate GRANT command to do that.)
IN GROUP rolename
IN GROUP is an obsolete spelling of IN ROLE.
ROLE rolename
The ROLE clause lists one or more existing roles which are
automatically added as members of the new role. (This in effect
makes the new role a ‘‘group’’.)
ADMIN rolename
The ADMIN clause is like ROLE, but the named roles are added to
the new role WITH ADMIN OPTION, giving them the right to grant
membership in this role to others.
USER rolename
The USER clause is an obsolete spelling of the ROLE clause.
SYSID uid
The SYSID clause is ignored, but is accepted for backwards
compatibility.
NOTES
Use ALTER ROLE [alter_role(7)] to change the attributes of a role, and
DROP ROLE [drop_role(7)] to remove a role. All the attributes specified
by CREATE ROLE can be modified by later ALTER ROLE commands.
The preferred way to add and remove members of roles that are being
used as groups is to use GRANT [grant(7)] and REVOKE [revoke(7)].
The VALID UNTIL clause defines an expiration time for a password only,
not for the role per se. In particular, the expiration time is not
enforced when logging in using a non-password-based authentication
method.
The INHERIT attribute governs inheritance of grantable privileges (that
is, access privileges for database objects and role memberships). It
does not apply to the special role attributes set by CREATE ROLE and
ALTER ROLE. For example, being a member of a role with CREATEDB
privilege does not immediately grant the ability to create databases,
even if INHERIT is set; it would be necessary to become that role via
SET ROLE [set_role(7)] before creating a database.
The INHERIT attribute is the default for reasons of backwards
compatibility: in prior releases of PostgreSQL, users always had access
to all privileges of groups they were members of. However, NOINHERIT
provides a closer match to the semantics specified in the SQL standard.
Be careful with the CREATEROLE privilege. There is no concept of
inheritance for the privileges of a CREATEROLE-role. That means that
even if a role does not have a certain privilege but is allowed to
create other roles, it can easily create another role with different
privileges than its own (except for creating roles with superuser
privileges). For example, if the role ‘‘user’’ has the CREATEROLE
privilege but not the CREATEDB privilege, nonetheless it can create a
new role with the CREATEDB privilege. Therefore, regard roles that have
the CREATEROLE privilege as almost-superuser-roles.
PostgreSQL includes a program createuser [createuser(1)] that has the
same functionality as CREATE ROLE (in fact, it calls this command) but
can be run from the command shell.
The CONNECTION LIMIT option is only enforced approximately; if two new
sessions start at about the same time when just one connection ‘‘slot’’
remains for the role, it is possible that both will fail. Also, the
limit is never enforced for superusers.
Caution must be exercised when specifying an unencrypted password with
this command. The password will be transmitted to the server in
cleartext, and it might also be logged in the client’s command history
or the server log. The command createuser [createuser(1)], however,
transmits the password encrypted. Also, psql [psql(1)] contains a
command \password that can be used to safely change the password later.
EXAMPLES
Create a role that can log in, but don’t give it a password:
CREATE ROLE jonathan LOGIN;
Create a role with a password:
CREATE USER davide WITH PASSWORD ’jw8s0F4’;
(CREATE USER is the same as CREATE ROLE except that it implies LOGIN.)
Create a role with a password that is valid until the end of 2004.
After one second has ticked in 2005, the password is no longer valid.
CREATE ROLE miriam WITH LOGIN PASSWORD ’jw8s0F4’ VALID UNTIL ’2005-01-01’;
Create a role that can create databases and manage roles:
CREATE ROLE admin WITH CREATEDB CREATEROLE;
COMPATIBILITY
The CREATE ROLE statement is in the SQL standard, but the standard only
requires the syntax
CREATE ROLE name [ WITH ADMIN rolename ]
Multiple initial administrators, and all the other options of CREATE
ROLE, are PostgreSQL extensions.
The SQL standard defines the concepts of users and roles, but it
regards them as distinct concepts and leaves all commands defining
users to be specified by each database implementation. In PostgreSQL we
have chosen to unify users and roles into a single kind of entity.
Roles therefore have many more optional attributes than they do in the
standard.
The behavior specified by the SQL standard is most closely approximated
by giving users the NOINHERIT attribute, while roles are given the
INHERIT attribute.
SEE ALSO
SET ROLE [set_role(7)], ALTER ROLE [alter_role(7)], DROP ROLE
[drop_role(7)], GRANT [grant(7)], REVOKE [revoke(7)], createuser(1)