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CREATE
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 alternate 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 may 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(5)] to change the attributes of a role, and DROP
ROLE [drop_role(5)] 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(5)] and REVOKE [revoke(5)].
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(5)] 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(5)], ALTER ROLE [alter_role(l)], DROP ROLE
[drop_role(l)], GRANT [grant(l)], REVOKE [revoke(l)], createuser(1)
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Index for
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Alphabetical
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