Movatterモバイル変換

CREATE ROLE
Prev	Up	SQL Commands	Home	Next

CREATE ROLE

CREATE ROLE — define a new database role

Synopsis

CREATE ROLEname [ [ WITH ]option [ ... ] ]whereoption can be:      SUPERUSER | NOSUPERUSER    | CREATEDB | NOCREATEDB    | CREATEROLE | NOCREATEROLE    | CREATEUSER | NOCREATEUSER    | INHERIT | NOINHERIT    | LOGIN | NOLOGIN    | REPLICATION | NOREPLICATION    | BYPASSRLS | NOBYPASSRLS    | CONNECTION LIMITconnlimit    | [ ENCRYPTED | UNENCRYPTED ] PASSWORD 'password'    | VALID UNTIL 'timestamp'    | IN ROLErole_name [, ...]    | IN GROUProle_name [, ...]    | ROLErole_name [, ...]    | ADMINrole_name [, ...]    | USERrole_name [, ...]    | SYSIDuid

Description

CREATE ROLE adds a new role to aPostgres Pro 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 toChapter 20 andChapter 19 for information about managing users and authentication. You must haveCREATEROLE 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. IfCREATEDB is specified, the role being defined will be allowed to create new databases. SpecifyingNOCREATEDB 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, executeCREATE ROLE). A role withCREATEROLE 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 ofSUPERUSER andNOSUPERUSER. Note that they arenot equivalent toCREATEROLE 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 theINHERIT attribute can automatically use whatever database privileges have been granted to all roles it is directly or indirectly a member of. WithoutINHERIT, membership in another role only grants the ability toSET 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 theLOGIN 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 whenCREATE ROLE is invoked through its alternative spellingCREATE USER.
REPLICATION NOREPLICATION: These clauses determine whether a role is allowed to initiate streaming replication or put the system in and out of backup mode. A role having theREPLICATION attribute is a very highly privileged role, and should only be used on roles actually used for replication. If not specified,NOREPLICATION is the default.
BYPASSRLS NOBYPASSRLS: These clauses determine whether a role bypasses every row-level security (RLS) policy.NOBYPASSRLS is the default. Note that pg_dump will setrow_security toOFF by default, to ensure all contents of a table are dumped out. If the user running pg_dump does not have appropriate permissions, an error will be returned. The superuser and owner of the table being dumped always bypass RLS.
CONNECTION LIMITconnlimit: If role can log in, this specifies how many concurrent connections the role can make. -1 (the default) means no limit.
PASSWORDpassword: Sets the role's password. (A password is only of use for roles having theLOGIN 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 asPASSWORD 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 parameterpassword_encryption.) If the presented password string is already in MD5-encrypted format, then it is stored encrypted as-is, regardless of whetherENCRYPTED orUNENCRYPTED is specified (since the system cannot decrypt the specified encrypted password string). This allows reloading of encrypted passwords during dump/restore.
VALID UNTIL 'timestamp': TheVALID 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 ROLErole_name: TheIN 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 separateGRANT command to do that.)
IN GROUProle_name: IN GROUP is an obsolete spelling ofIN ROLE.
ROLErole_name: TheROLE 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”.)
ADMINrole_name: TheADMIN clause is likeROLE, but the named roles are added to the new roleWITH ADMIN OPTION, giving them the right to grant membership in this role to others.
USERrole_name: TheUSER clause is an obsolete spelling of theROLE clause.
SYSIDuid: TheSYSID clause is ignored, but is accepted for backwards compatibility.

Notes

UseALTER ROLE to change the attributes of a role, andDROP ROLE to remove a role. All the attributes specified byCREATE ROLE can be modified by laterALTER ROLE commands.

The preferred way to add and remove members of roles that are being used as groups is to useGRANT andREVOKE.

TheVALID UNTIL clause defines an expiration time for a password only, not for the roleper se. In particular, the expiration time is not enforced when logging in using a non-password-based authentication method.

TheINHERIT 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 byCREATE ROLE andALTER ROLE. For example, being a member of a role withCREATEDB privilege does not immediately grant the ability to create databases, even ifINHERIT is set; it would be necessary to become that role viaSET ROLE before creating a database.

TheINHERIT attribute is the default for reasons of backwards compatibility: in prior releases ofPostgres Pro, 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 theCREATEROLE privilege. There is no concept of inheritance for the privileges of aCREATEROLE-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 theCREATEROLE privilege but not theCREATEDB privilege, nonetheless it can create a new role with theCREATEDB privilege. Therefore, regard roles that have theCREATEROLE privilege as almost-superuser-roles.

Postgres Pro includes a programcreateuser that has the same functionality asCREATE ROLE (in fact, it calls this command) but can be run from the command shell.

TheCONNECTION 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 commandcreateuser, 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:

CREATE ROLE jonathan LOGIN;

Create a role with a password:

CREATE USER davide WITH PASSWORD 'jw8s0F4';

(CREATE USER is the same asCREATE ROLE except that it impliesLOGIN.)

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

TheCREATE ROLE statement is in the SQL standard, but the standard only requires the syntax

CREATE ROLEname [ WITH ADMINrole_name ]

Multiple initial administrators, and all the other options ofCREATE ROLE, arePostgres Pro 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. InPostgres Pro 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 theNOINHERIT attribute, while roles are given theINHERIT attribute.