|PostgreSQL Reference Manual - Volume 1 - SQL Language Reference|
by The PostgreSQL Global Development Group
Paperback (6"x9"), 716 pages
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12.103 SET ROLE
SET ROLE -- set the current user identifier of the current session
SET [ SESSION | LOCAL ] ROLE rolename SET [ SESSION | LOCAL ] ROLE NONE RESET ROLE
This command sets the current user
identifier of the current SQL-session context to be rolename. The role name may be
written as either an identifier or a string literal.
SET ROLE, permissions checking for SQL commands
is carried out as though the named role were the one that had logged
The specified rolename must be a role that the current session user is a member of. (If the session user is a superuser, any role can be selected.)
LOCAL modifiers act the same
as for the regular
RESET forms reset the current
user identifier to be the current session user identifier.
These forms may be executed by any user.
Using this command, it is possible to either add privileges or restrict
one's privileges. If the session user role has the
attribute, then it automatically has all the privileges of every role that
SET ROLE to; in this case
effectively drops all the privileges assigned directly to the session user
and to the other roles it is a member of, leaving only the privileges
available to the named role. On the other hand, if the session user role
SET ROLE drops the
privileges assigned directly to the session user and instead acquires the
privileges available to the named role.
In particular, when a superuser chooses to
SET ROLE to a
non-superuser role, she loses her superuser privileges.
SET ROLE has effects comparable to
SET SESSION AUTHORIZATION, but the privilege
checks involved are quite different. Also,
SET SESSION AUTHORIZATION determines which roles are
allowable for later
SET ROLE commands, whereas changing
SET ROLE does not change the set of roles
allowed to a later
SELECT SESSION_USER, CURRENT_USER; session_user | current_user --------------+-------------- peter | peter SET ROLE 'paul'; SELECT SESSION_USER, CURRENT_USER; session_user | current_user --------------+-------------- peter | paul
allows identifier syntax (
the SQL standard requires the role name to be written as a string
literal. SQL does not allow this command during a transaction;
PostgreSQL does not make this
restriction because there is no reason to.
LOCAL modifiers are a
PostgreSQL extension, as is the
|ISBN 0954612027||PostgreSQL Reference Manual - Volume 1 - SQL Language Reference||See the print edition|