|The PostgreSQL 9.0 Reference Manual - Volume 1B - SQL Command Reference
by The PostgreSQL Global Development Group
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1.54 CREATE ROLE
CREATE ROLE -- define a new database role
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 role_name [, ...] | IN GROUP role_name [, ...] | ROLE role_name [, ...] | ADMIN role_name [, ...] | USER role_name [, ...] | SYSID uid
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
Volume 3: Database Roles and Privileges and Volume 3: Client Authentication for information about managing
users and authentication. You must have
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.
- The name of the new role.
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,
NOSUPERUSERis the default.
These clauses define a role's ability to create databases. If
CREATEDBis specified, the role being defined will be allowed to create new databases. Specifying
NOCREATEDBwill deny a role the ability to create databases. If not specified,
NOCREATEDBis the default.
These clauses determine whether a role will be permitted to
create new roles (that is, execute
CREATE ROLE). A role with
CREATEROLEprivilege can also alter and drop other roles. If not specified,
NOCREATEROLEis the default.
These clauses are an obsolete, but still accepted, spelling of
NOSUPERUSER. Note that they are not equivalent to
CREATEROLEas one might naively expect!
These clauses determine whether a role “inherits” the
privileges of roles it is a member of.
A role with the
INHERITattribute 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 ROLEto that other role; the privileges of the other role are only available after having done so. If not specified,
INHERITis the default.
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
LOGINattribute 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,
NOLOGINis the default, except when
CREATE ROLEis invoked through its alternative spelling
- If role can log in, this specifies how many concurrent connections the role can make. -1 (the default) means no limit.
Sets the role's password. (A password is only of use for
roles having the
LOGINattribute, 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
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
password_encryption.) If the presented password string is already in MD5-encrypted format, then it is stored encrypted as-is, regardless of whether
UNENCRYPTEDis 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 UNTILclause 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 ROLEclause 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
GRANTcommand to do that.)
IN GROUPis an obsolete spelling of
ROLEclause 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”.)
ADMINclause 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.
USERclause is an obsolete spelling of the
SYSIDclause is ignored, but is accepted for backwards compatibility.
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.
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 before
creating a database.
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.
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
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
nonetheless it can create a new role with the
privilege. Therefore, regard roles that have the
privilege as almost-superuser-roles.
PostgreSQL includes a program
createuser that has
the same functionality as
CREATE ROLE (in fact,
it calls this command) but can be run from the command shell.
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, however, transmits
the password encrypted. Also,
contains a command
\password that can be used to safely change the
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
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;
CREATE ROLE statement is in the SQL standard,
but the standard only requires the syntax
CREATE ROLE name [ WITH ADMIN role_name ]
Multiple initial administrators, and all the other options of
CREATE ROLE, are
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
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