2 doc/src/sgml/ref/set_role.sgml
3 PostgreSQL documentation
6 <refentry id="SQL-SET-ROLE">
8 <refentrytitle>SET ROLE</refentrytitle>
9 <manvolnum>7</manvolnum>
10 <refmiscinfo>SQL - Language Statements</refmiscinfo>
14 <refname>SET ROLE</refname>
15 <refpurpose>set the current user identifier of the current session</refpurpose>
18 <indexterm zone="sql-set-role">
19 <primary>SET ROLE</primary>
24 SET [ SESSION | LOCAL ] ROLE <replaceable class="parameter">role_name</replaceable>
25 SET [ SESSION | LOCAL ] ROLE NONE
31 <title>Description</title>
34 This command sets the current user
35 identifier of the current SQL session to be <replaceable
36 class="parameter">role_name</replaceable>. The role name can be
37 written as either an identifier or a string literal.
38 After <command>SET ROLE</>, permissions checking for SQL commands
39 is carried out as though the named role were the one that had logged
44 The specified <replaceable class="parameter">role_name</replaceable>
45 must be a role that the current session user is a member of.
46 (If the session user is a superuser, any role can be selected.)
50 The <literal>SESSION</> and <literal>LOCAL</> modifiers act the same
51 as for the regular <xref linkend="SQL-SET">
56 The <literal>NONE</> and <literal>RESET</> forms reset the current
57 user identifier to be the current session user identifier.
58 These forms can be executed by any user.
66 Using this command, it is possible to either add privileges or restrict
67 one's privileges. If the session user role has the <literal>INHERITS</>
68 attribute, then it automatically has all the privileges of every role that
69 it could <command>SET ROLE</> to; in this case <command>SET ROLE</>
70 effectively drops all the privileges assigned directly to the session user
71 and to the other roles it is a member of, leaving only the privileges
72 available to the named role. On the other hand, if the session user role
73 has the <literal>NOINHERITS</> attribute, <command>SET ROLE</> drops the
74 privileges assigned directly to the session user and instead acquires the
75 privileges available to the named role.
79 In particular, when a superuser chooses to <command>SET ROLE</> to a
80 non-superuser role, she loses her superuser privileges.
84 <command>SET ROLE</> has effects comparable to
85 <xref linkend="sql-set-session-authorization">, but the privilege
86 checks involved are quite different. Also,
87 <command>SET SESSION AUTHORIZATION</> determines which roles are
88 allowable for later <command>SET ROLE</> commands, whereas changing
89 roles with <command>SET ROLE</> does not change the set of roles
90 allowed to a later <command>SET ROLE</>.
94 <command>SET ROLE</> does not process session variables as specified by
95 the role's <xref linkend="sql-alterrole"> settings; this only happens during
100 <command>SET ROLE</> cannot be used within a
101 <literal>SECURITY DEFINER</> function.
106 <title>Examples</title>
109 SELECT SESSION_USER, CURRENT_USER;
111 session_user | current_user
112 --------------+--------------
117 SELECT SESSION_USER, CURRENT_USER;
119 session_user | current_user
120 --------------+--------------
126 <title>Compatibility</title>
129 <productname>PostgreSQL</productname>
130 allows identifier syntax (<literal>"rolename"</literal>), while
131 the SQL standard requires the role name to be written as a string
132 literal. SQL does not allow this command during a transaction;
133 <productname>PostgreSQL</productname> does not make this
134 restriction because there is no reason to.
135 The <literal>SESSION</> and <literal>LOCAL</> modifiers are a
136 <productname>PostgreSQL</productname> extension, as is the
137 <literal>RESET</> syntax.
142 <title>See Also</title>
144 <simplelist type="inline">
145 <member><xref linkend="sql-set-session-authorization"></member>