CREATE ROLE

Defines a new database role (user or group).

Synopsis

  1. CREATE ROLE <name> [[WITH] <option> [ ... ]]

where <option> can be:

  1.       SUPERUSER | NOSUPERUSER
  2.     | CREATEDB | NOCREATEDB
  3.     | CREATEROLE | NOCREATEROLE
  4.     | CREATEEXTTABLE | NOCREATEEXTTABLE
  5.       [ ( <attribute>='<value>'[, ...] ) ]
  6.            where attribute and value are:
  7.            type='readable'|'writable'
  8.            protocol='gpfdist'|'http'
  9.     | INHERIT | NOINHERIT
  10.     | LOGIN | NOLOGIN
  11.     | CONNECTION LIMIT <connlimit>
  12.     | [ ENCRYPTED | UNENCRYPTED ] PASSWORD '<password>'
  13.     | VALID UNTIL '<timestamp>'
  14.     | IN ROLE <rolename> [, ...]
  15.     | ROLE <rolename> [, ...]
  16.     | ADMIN <rolename> [, ...]
  17.     | RESOURCE QUEUE <queue_name>
  18.     | [ DENY <deny_point> ]
  19.     | [ DENY BETWEEN <deny_point> AND <deny_point>]

Description

CREATE ROLE adds a new role to a HAWQ system. 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. You must have CREATEROLE privilege or be a database superuser to use this command.

Note that roles are defined at the system-level and are valid for all databases in your HAWQ system.

Parameters

<name>

The name of the new role.

SUPERUSER,
NOSUPERUSER

If SUPERUSER is specified, the role being defined will be 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. NOSUPERUSER is the default.

CREATEDB,
NOCREATEDB

If CREATEDB is specified, the role being defined will be allowed to create new databases. NOCREATEDB (the default) will deny a role the ability to create databases.

CREATEROLE,
NOCREATEROLE

If CREATEDB is specified, the role being defined will be allowed to create new roles, alter other roles, and drop other roles. NOCREATEROLE (the default) will deny a role the ability to create roles or modify roles other than their own.

CREATEEXTTABLE,
NOCREATEEXTTABLE

If CREATEEXTTABLE is specified, the role being defined is allowed to create external tables. The default <type> is readable and the default protocol is gpfdist if not specified. NOCREATEEXTTABLE (the default) denies the role the ability to create external tables. Using the file protocol when creating external tables is not supported. This is because HAWQ cannot guarantee scheduling executors on a specific host. Likewise, you cannot use the EXECUTE command with ON ALL and ON HOST for the same reason. Use the ON MASTER/number/SEGMENT segment_id to specify which segment instances are to execute the command.

INHERIT,
NOINHERIT

If specified, INHERIT (the default) allows the role to use whatever database privileges have been granted to all roles it is directly or indirectly a member of. With NOINHERIT, membership in another role only grants the ability to SET ROLE to that other role.

LOGIN,
NOLOGIN

If specified, LOGIN allows a role to log in to a database. A role having the LOGIN attribute can be thought of as a user. Roles with NOLOGIN (the default) are useful for managing database privileges, and can be thought of as groups.

CONNECTION LIMIT <connlimit>

The number maximum of concurrent connections this role can make. The default of -1 means there is no limitation.

PASSWORD <password>

Sets the user password for roles with the LOGIN attribute. 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 never expire.

IN ROLE <rolename>

Adds the new role as a member of the named roles. Note that there is no option to add the new role as an administrator; use a separate GRANT command to do that.

ROLE <rolename>

Adds the named roles as members of this role, making this 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.

RESOURCE QUEUE <queue_name>

The name of the resource queue to which the new user-level role is to be assigned. Only roles with LOGIN privilege can be assigned to a resource queue. The special keyword NONE means that the role is assigned to the default resource queue. A role can only belong to one resource queue.

DENY <deny_point>,
DENY BETWEEN <deny_point> AND <deny_point>

The DENY and DENY BETWEEN keywords set time-based constraints that are enforced at login. DENY sets a day or a day and time to deny access. DENY BETWEEN sets an interval during which access is denied. Both use the parameter <deny_point> that has the following format:

  1. DAY <day> [ TIME '<time>' ]

The two parts of the <deny_point> parameter use the following formats:

For <day>:

  1. {'Sunday' | 'Monday' | 'Tuesday' |'Wednesday' | 'Thursday' | 'Friday' |
  2. 'Saturday' | 0-6 }

For <time>:

  1. { 00-23 : 00-59 | 01-12 : 00-59 { AM | PM }}

The DENY BETWEEN clause uses two <deny_point> parameters:

  1. DENY BETWEEN deny_point AND deny_point

Notes

The preferred way to add and remove role members (manage groups) is to use GRANT and REVOKE.

The VALID UNTIL clause defines an expiration time for a password only, not for the role. The expiration time is not enforced when logging in using a non-password-based authentication method.

The INHERIT attribute governs inheritance of grantable privileges (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.

The INHERIT attribute is the default for reasons of backwards compatibility. In prior releases of HAWQ, 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 a role has the CREATEROLE privilege but not the CREATEDB privilege, it can create a new role with the CREATEDB privilege. Therefore, regard roles that have the CREATEROLE privilege as almost-superuser-roles.

The CONNECTION LIMIT option 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 clear-text, and it might also be logged in the client’s command history or the server log. The client program createuser, however, transmits the password encrypted. Also, psql 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:

  1. CREATE ROLE jonathan LOGIN;

Create a role that belongs to a resource queue:

  1. CREATE ROLE jonathan LOGIN RESOURCE QUEUE poweruser;

Create a role with a password that is valid until the end of 2009 (CREATE USER is the same as CREATE ROLE except that it implies LOGIN):

  1. CREATE USER joelle WITH PASSWORD 'jw8s0F4' VALID UNTIL '2010-01-01';

Create a role that can create databases and manage other roles:

  1. CREATE ROLE admin WITH CREATEDB CREATEROLE;

Create a role that does not allow login access on Sundays:

  1. CREATE ROLE user3 DENY DAY 'Sunday';

Compatibility

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 the database implementation. In HAWQ, users and roles are unified into a single type of object. Roles therefore have many more optional attributes than they do in the standard.

CREATE ROLE is in the SQL standard, but the standard only requires the syntax:

  1. CREATE ROLE <name> [WITH ADMIN <rolename>]

Allowing multiple initial administrators, and all the other options of CREATE ROLE, are HAWQ extensions.

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, ALTER ROLE, DROP ROLE, GRANT, REVOKE, CREATE RESOURCE QUEUE