doc/src/sgml/ref/revoke.sgml

<!--
$PostgreSQL: pgsql/doc/src/sgml/ref/revoke.sgml,v 1.41 2006/09/16 00:30:19 momjian Exp $
PostgreSQL documentation
-->

<refentry id="SQL-REVOKE">
 <refmeta>
  <refentrytitle id="sql-revoke-title">REVOKE</refentrytitle>
  <refmiscinfo>SQL - Language Statements</refmiscinfo>
 </refmeta>

 <refnamediv>
  <refname>REVOKE</refname>
  <refpurpose>remove access privileges</refpurpose>
 </refnamediv>

 <indexterm zone="sql-revoke">
  <primary>REVOKE</primary>
 </indexterm>

 <refsynopsisdiv>
<synopsis>
REVOKE [ GRANT OPTION FOR ]
    { { SELECT | INSERT | UPDATE | DELETE | REFERENCES | TRIGGER }
    [,...] | ALL [ PRIVILEGES ] }
    ON [ TABLE ] <replaceable class="PARAMETER">tablename</replaceable> [, ...]
    FROM { <replaceable class="PARAMETER">username</replaceable> | GROUP <replaceable class="PARAMETER">groupname</replaceable> | PUBLIC } [, ...]
    [ CASCADE | RESTRICT ]

REVOKE [ GRANT OPTION FOR ]
    { { USAGE | SELECT | UPDATE }
    [,...] | ALL [ PRIVILEGES ] }
    ON SEQUENCE <replaceable class="PARAMETER">sequencename</replaceable> [, ...]
    FROM { <replaceable class="PARAMETER">username</replaceable> | GROUP <replaceable class="PARAMETER">groupname</replaceable> | PUBLIC } [, ...]
    [ CASCADE | RESTRICT ]

REVOKE [ GRANT OPTION FOR ]
    { { CREATE | CONNECT | TEMPORARY | TEMP } [,...] | ALL [ PRIVILEGES ] }
    ON DATABASE <replaceable>dbname</replaceable> [, ...]
    FROM { <replaceable class="PARAMETER">username</replaceable> | GROUP <replaceable class="PARAMETER">groupname</replaceable> | PUBLIC } [, ...]
    [ CASCADE | RESTRICT ]

REVOKE [ GRANT OPTION FOR ]
    { EXECUTE | ALL [ PRIVILEGES ] }
    ON FUNCTION <replaceable>funcname</replaceable> ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] ) [, ...]
    FROM { <replaceable class="PARAMETER">username</replaceable> | GROUP <replaceable class="PARAMETER">groupname</replaceable> | PUBLIC } [, ...]
    [ CASCADE | RESTRICT ]

REVOKE [ GRANT OPTION FOR ]
    { USAGE | ALL [ PRIVILEGES ] }
    ON LANGUAGE <replaceable>langname</replaceable> [, ...]
    FROM { <replaceable class="PARAMETER">username</replaceable> | GROUP <replaceable class="PARAMETER">groupname</replaceable> | PUBLIC } [, ...]
    [ CASCADE | RESTRICT ]

REVOKE [ GRANT OPTION FOR ]
    { { CREATE | USAGE } [,...] | ALL [ PRIVILEGES ] }
    ON SCHEMA <replaceable>schemaname</replaceable> [, ...]
    FROM { <replaceable class="PARAMETER">username</replaceable> | GROUP <replaceable class="PARAMETER">groupname</replaceable> | PUBLIC } [, ...]
    [ CASCADE | RESTRICT ]

REVOKE [ GRANT OPTION FOR ]
    { CREATE | ALL [ PRIVILEGES ] }
    ON TABLESPACE <replaceable>tablespacename</replaceable> [, ...]
    FROM { <replaceable class="PARAMETER">username</replaceable> | GROUP <replaceable class="PARAMETER">groupname</replaceable> | PUBLIC } [, ...]
    [ CASCADE | RESTRICT ]

REVOKE [ ADMIN OPTION FOR ]
    <replaceable class="PARAMETER">role</replaceable> [, ...] FROM <replaceable class="PARAMETER">username</replaceable> [, ...]
    [ CASCADE | RESTRICT ]
</synopsis>
 </refsynopsisdiv>

 <refsect1 id="SQL-REVOKE-description">
  <title>Description</title>

  <para>
   The <command>REVOKE</command> command revokes previously granted
   privileges from one or more roles.  The key word
   <literal>PUBLIC</literal> refers to the implicitly defined group of
   all roles.
  </para>

  <para>
   See the description of the <xref linkend="sql-grant" endterm="sql-grant-title"> command for
   the meaning of the privilege types.
  </para>

  <para>
   Note that any particular role will have the sum
   of privileges granted directly to it, privileges granted to any role it
   is presently a member of, and privileges granted to
   <literal>PUBLIC</literal>.  Thus, for example, revoking <literal>SELECT</> privilege
   from <literal>PUBLIC</literal> does not necessarily mean that all roles
   have lost <literal>SELECT</> privilege on the object: those who have it granted
   directly or via another role will still have it.
  </para>

  <para>
   If <literal>GRANT OPTION FOR</literal> is specified, only the grant
   option for the privilege is revoked, not the privilege itself.
   Otherwise, both the privilege and the grant option are revoked.
  </para>

  <para>
   If a user holds a privilege with grant option and has granted it to
   other users then the privileges held by those other users are
   called dependent privileges. If the privilege or the grant option
   held by the first user is being revoked and dependent privileges
   exist, those dependent privileges are also revoked if
   <literal>CASCADE</literal> is specified, else the revoke action
   will fail.  This recursive revocation only affects privileges that
   were granted through a chain of users that is traceable to the user
   that is the subject of this <literal>REVOKE</literal> command.
   Thus, the affected users may effectively keep the privilege if it
   was also granted through other users.
  </para>

  <para>
   When revoking membership in a role, <literal>GRANT OPTION</> is instead
   called <literal>ADMIN OPTION</>, but the behavior is similar.
   Note also that this form of the command does not
   allow the noise word <literal>GROUP</>.
  </para>
 </refsect1>

 <refsect1 id="SQL-REVOKE-notes">
  <title>Notes</title>

  <para>
   Use <xref linkend="app-psql">'s <command>\z</command> command to
   display the privileges granted on existing objects.  See <xref
   linkend="sql-grant" endterm="sql-grant-title"> for information about the format.
  </para>

  <para>
   A user can only revoke privileges that were granted directly by
   that user.  If, for example, user A has granted a privilege with
   grant option to user B, and user B has in turned granted it to user
   C, then user A cannot revoke the privilege directly from C.
   Instead, user A could revoke the grant option from user B and use
   the <literal>CASCADE</literal> option so that the privilege is
   in turn revoked from user C.  For another example, if both A and B
   have granted the same privilege to C, A can revoke his own grant
   but not B's grant, so C will still effectively have the privilege.
  </para>

   <para>
    When a non-owner of an object attempts to <command>REVOKE</> privileges
    on the object, the command will fail outright if the user has no
    privileges whatsoever on the object.  As long as some privilege is
    available, the command will proceed, but it will revoke only those
    privileges for which the user has grant options.  The <command>REVOKE ALL
    PRIVILEGES</> forms will issue a warning message if no grant options are
    held, while the other forms will issue a warning if grant options for
    any of the privileges specifically named in the command are not held.
    (In principle these statements apply to the object owner as well, but
    since the owner is always treated as holding all grant options, the
    cases can never occur.)
   </para>

   <para>
    If a superuser chooses to issue a <command>GRANT</> or <command>REVOKE</>
    command, the command is performed as though it were issued by the
    owner of the affected object.  Since all privileges ultimately come
    from the object owner (possibly indirectly via chains of grant options),
    it is possible for a superuser to revoke all privileges, but this may
    require use of <literal>CASCADE</literal> as stated above.
   </para>

   <para>
    <command>REVOKE</> can also be done by a role
    that is not the owner of the affected object, but is a member of the role
    that owns the object, or is a member of a role that holds privileges
    <literal>WITH GRANT OPTION</literal> on the object.  In this case the
    command is performed as though it were issued by the containing role that
    actually owns the object or holds the privileges
    <literal>WITH GRANT OPTION</literal>.  For example, if table
    <literal>t1</> is owned by role <literal>g1</>, of which role
    <literal>u1</> is a member, then <literal>u1</> can revoke privileges
    on <literal>t1</> that are recorded as being granted by <literal>g1</>.
    This would include grants made by <literal>u1</> as well as by other
    members of role <literal>g1</>.
   </para>

   <para>
    If the role executing <command>REVOKE</> holds privileges
    indirectly via more than one role membership path, it is unspecified
    which containing role will be used to perform the command.  In such cases
    it is best practice to use <command>SET ROLE</> to become the specific
    role you want to do the <command>REVOKE</> as.  Failure to do so may
    lead to revoking privileges other than the ones you intended, or not
    revoking anything at all.
   </para>
 </refsect1>

 <refsect1 id="SQL-REVOKE-examples">
  <title>Examples</title>

  <para>
   Revoke insert privilege for the public on table
   <literal>films</literal>:

<programlisting>
REVOKE INSERT ON films FROM PUBLIC;
</programlisting>
  </para>

  <para>
   Revoke all privileges from user <literal>manuel</literal> on view
   <literal>kinds</literal>:

<programlisting>
REVOKE ALL PRIVILEGES ON kinds FROM manuel;
</programlisting>

   Note that this actually means <quote>revoke all privileges that I
   granted</>.
  </para>

  <para>
   Revoke membership in role <literal>admins</> from user <literal>joe</>:

<programlisting>
REVOKE admins FROM joe;
</programlisting>
  </para>
 </refsect1>

 <refsect1 id="SQL-REVOKE-compatibility">
  <title>Compatibility</title>

   <para>
    The compatibility notes of the <xref linkend="sql-grant" endterm="sql-grant-title"> command
    apply analogously to <command>REVOKE</command>.  The syntax summary is:

<synopsis>
REVOKE [ GRANT OPTION FOR ] <replaceable class="PARAMETER">privileges</replaceable>
    ON <replaceable class="parameter">object</replaceable> [ ( <replaceable class="parameter">column</replaceable> [, ...] ) ]
    FROM { PUBLIC | <replaceable class="parameter">username</replaceable> [, ...] }
    { RESTRICT | CASCADE }
</synopsis>
    One of <literal>RESTRICT</literal> or <literal>CASCADE</literal>
    is required according to the standard, but <productname>PostgreSQL</>
    assumes <literal>RESTRICT</literal> by default.
   </para>
 </refsect1>

 <refsect1>
  <title>See Also</title>

  <simpara>
   <xref linkend="sql-grant" endterm="sql-grant-title">
  </simpara>
 </refsect1>

</refentry>