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   3 ALTER FUNCTION <em class="replaceable"><code>name</code></em> [ ( [ [ <em class="replaceable"><code>argmode</code></em> ] [ <em class="replaceable"><code>argname</code></em> ] <em class="replaceable"><code>argtype</code></em> [, ...] ] ) ]
   4     <em class="replaceable"><code>action</code></em> [ ... ] [ RESTRICT ]
   5 ALTER FUNCTION <em class="replaceable"><code>name</code></em> [ ( [ [ <em class="replaceable"><code>argmode</code></em> ] [ <em class="replaceable"><code>argname</code></em> ] <em class="replaceable"><code>argtype</code></em> [, ...] ] ) ]
   6     RENAME TO <em class="replaceable"><code>new_name</code></em>
   7 ALTER FUNCTION <em class="replaceable"><code>name</code></em> [ ( [ [ <em class="replaceable"><code>argmode</code></em> ] [ <em class="replaceable"><code>argname</code></em> ] <em class="replaceable"><code>argtype</code></em> [, ...] ] ) ]
   8     OWNER TO { <em class="replaceable"><code>new_owner</code></em> | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
   9 ALTER FUNCTION <em class="replaceable"><code>name</code></em> [ ( [ [ <em class="replaceable"><code>argmode</code></em> ] [ <em class="replaceable"><code>argname</code></em> ] <em class="replaceable"><code>argtype</code></em> [, ...] ] ) ]
  10     SET SCHEMA <em class="replaceable"><code>new_schema</code></em>
  11 ALTER FUNCTION <em class="replaceable"><code>name</code></em> [ ( [ [ <em class="replaceable"><code>argmode</code></em> ] [ <em class="replaceable"><code>argname</code></em> ] <em class="replaceable"><code>argtype</code></em> [, ...] ] ) ]
  12     [ NO ] DEPENDS ON EXTENSION <em class="replaceable"><code>extension_name</code></em>
  13
  14 <span class="phrase">where <em class="replaceable"><code>action</code></em> is one of:</span>
  15
  16     CALLED ON NULL INPUT | RETURNS NULL ON NULL INPUT | STRICT
  17     IMMUTABLE | STABLE | VOLATILE
  18     [ NOT ] LEAKPROOF
  19     [ EXTERNAL ] SECURITY INVOKER | [ EXTERNAL ] SECURITY DEFINER
  20     PARALLEL { UNSAFE | RESTRICTED | SAFE }
  21     COST <em class="replaceable"><code>execution_cost</code></em>
  22     ROWS <em class="replaceable"><code>result_rows</code></em>
  23     SUPPORT <em class="replaceable"><code>support_function</code></em>
  24     SET <em class="replaceable"><code>configuration_parameter</code></em> { TO | = } { <em class="replaceable"><code>value</code></em> | DEFAULT }
  25     SET <em class="replaceable"><code>configuration_parameter</code></em> FROM CURRENT
  26     RESET <em class="replaceable"><code>configuration_parameter</code></em>
  27     RESET ALL
  28 </pre></div><div class="refsect1" id="id-1.9.3.14.5"><h2>Description</h2><p>
  29    <code class="command">ALTER FUNCTION</code> changes the definition of a
  30    function.
  31   </p><p>
  32    You must own the function to use <code class="command">ALTER FUNCTION</code>.
  33    To change a function's schema, you must also have <code class="literal">CREATE</code>
  34    privilege on the new schema.  To alter the owner, you must be able to
  35    <code class="literal">SET ROLE</code> to the new owning role, and that role must
  36    have <code class="literal">CREATE</code> privilege on
  37    the function's schema.  (These restrictions enforce that altering the owner
  38    doesn't do anything you couldn't do by dropping and recreating the function.
  39    However, a superuser can alter ownership of any function anyway.)
  40   </p></div><div class="refsect1" id="id-1.9.3.14.6"><h2>Parameters</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="replaceable"><code>name</code></em></span></dt><dd><p>
  41       The name (optionally schema-qualified) of an existing function.  If no
  42       argument list is specified, the name must be unique in its schema.
  43      </p></dd><dt><span class="term"><em class="replaceable"><code>argmode</code></em></span></dt><dd><p>
  44       The mode of an argument: <code class="literal">IN</code>, <code class="literal">OUT</code>,
  45       <code class="literal">INOUT</code>, or <code class="literal">VARIADIC</code>.
  46       If omitted, the default is <code class="literal">IN</code>.
  47       Note that <code class="command">ALTER FUNCTION</code> does not actually pay
  48       any attention to <code class="literal">OUT</code> arguments, since only the input
  49       arguments are needed to determine the function's identity.
  50       So it is sufficient to list the <code class="literal">IN</code>, <code class="literal">INOUT</code>,
  51       and <code class="literal">VARIADIC</code> arguments.
  52      </p></dd><dt><span class="term"><em class="replaceable"><code>argname</code></em></span></dt><dd><p>
  53       The name of an argument.
  54       Note that <code class="command">ALTER FUNCTION</code> does not actually pay
  55       any attention to argument names, since only the argument data
  56       types are needed to determine the function's identity.
  57      </p></dd><dt><span class="term"><em class="replaceable"><code>argtype</code></em></span></dt><dd><p>
  58       The data type(s) of the function's arguments (optionally
  59       schema-qualified), if any.
  60      </p></dd><dt><span class="term"><em class="replaceable"><code>new_name</code></em></span></dt><dd><p>
  61       The new name of the function.
  62      </p></dd><dt><span class="term"><em class="replaceable"><code>new_owner</code></em></span></dt><dd><p>
  63       The new owner of the function.  Note that if the function is
  64       marked <code class="literal">SECURITY DEFINER</code>, it will subsequently
  65       execute as the new owner.
  66      </p></dd><dt><span class="term"><em class="replaceable"><code>new_schema</code></em></span></dt><dd><p>
  67       The new schema for the function.
  68      </p></dd><dt><span class="term"><code class="literal">DEPENDS ON EXTENSION <em class="replaceable"><code>extension_name</code></em></code><br /></span><span class="term"><code class="literal">NO DEPENDS ON EXTENSION <em class="replaceable"><code>extension_name</code></em></code></span></dt><dd><p>
  69       This form marks the function as dependent on the extension, or no longer
  70       dependent on that extension if <code class="literal">NO</code> is specified.
  71       A function that's marked as dependent on an extension is dropped when the
  72       extension is dropped, even if <code class="literal">CASCADE</code> is not specified.
  73       A function can depend upon multiple extensions, and will be dropped when
  74       any one of those extensions is dropped.
  75      </p></dd><dt><span class="term"><code class="literal">CALLED ON NULL INPUT</code><br /></span><span class="term"><code class="literal">RETURNS NULL ON NULL INPUT</code><br /></span><span class="term"><code class="literal">STRICT</code></span></dt><dd><p><code class="literal">CALLED ON NULL INPUT</code> changes the function so
  76        that it will be invoked when some or all of its arguments are
  77        null. <code class="literal">RETURNS NULL ON NULL INPUT</code> or
  78        <code class="literal">STRICT</code> changes the function so that it is not
  79        invoked if any of its arguments are null; instead, a null result
  80        is assumed automatically.  See <a class="xref" href="sql-createfunction.html" title="CREATE FUNCTION"><span class="refentrytitle">CREATE FUNCTION</span></a>
  81        for more information.
  82       </p></dd><dt><span class="term"><code class="literal">IMMUTABLE</code><br /></span><span class="term"><code class="literal">STABLE</code><br /></span><span class="term"><code class="literal">VOLATILE</code></span></dt><dd><p>
  83        Change the volatility of the function to the specified setting.
  84        See <a class="xref" href="sql-createfunction.html" title="CREATE FUNCTION"><span class="refentrytitle">CREATE FUNCTION</span></a> for details.
  85       </p></dd><dt><span class="term"><code class="literal">[<span class="optional"> EXTERNAL </span>] SECURITY INVOKER</code><br /></span><span class="term"><code class="literal">[<span class="optional"> EXTERNAL </span>] SECURITY DEFINER</code></span></dt><dd><p>
  86       Change whether the function is a security definer or not. The
  87       key word <code class="literal">EXTERNAL</code> is ignored for SQL
  88       conformance. See <a class="xref" href="sql-createfunction.html" title="CREATE FUNCTION"><span class="refentrytitle">CREATE FUNCTION</span></a> for more information about
  89       this capability.
  90      </p></dd><dt><span class="term"><code class="literal">PARALLEL</code></span></dt><dd><p>
  91       Change whether the function is deemed safe for parallelism.
  92       See <a class="xref" href="sql-createfunction.html" title="CREATE FUNCTION"><span class="refentrytitle">CREATE FUNCTION</span></a> for details.
  93      </p></dd><dt><span class="term"><code class="literal">LEAKPROOF</code></span></dt><dd><p>
  94       Change whether the function is considered leakproof or not.
  95       See <a class="xref" href="sql-createfunction.html" title="CREATE FUNCTION"><span class="refentrytitle">CREATE FUNCTION</span></a> for more information about
  96       this capability.
  97      </p></dd><dt><span class="term"><code class="literal">COST</code> <em class="replaceable"><code>execution_cost</code></em></span></dt><dd><p>
  98        Change the estimated execution cost of the function.
  99        See <a class="xref" href="sql-createfunction.html" title="CREATE FUNCTION"><span class="refentrytitle">CREATE FUNCTION</span></a> for more information.
 100       </p></dd><dt><span class="term"><code class="literal">ROWS</code> <em class="replaceable"><code>result_rows</code></em></span></dt><dd><p>
 101        Change the estimated number of rows returned by a set-returning
 102        function.  See <a class="xref" href="sql-createfunction.html" title="CREATE FUNCTION"><span class="refentrytitle">CREATE FUNCTION</span></a> for more information.
 103       </p></dd><dt><span class="term"><code class="literal">SUPPORT</code> <em class="replaceable"><code>support_function</code></em></span></dt><dd><p>
 104       Set or change the planner support function to use for this function.
 105       See <a class="xref" href="xfunc-optimization.html" title="36.11. Function Optimization Information">Section 36.11</a> for details.  You must be
 106       superuser to use this option.
 107      </p><p>
 108       This option cannot be used to remove the support function altogether,
 109       since it must name a new support function.  Use <code class="command">CREATE OR
 110       REPLACE FUNCTION</code> if you need to do that.
 111      </p></dd><dt><span class="term"><em class="replaceable"><code>configuration_parameter</code></em><br /></span><span class="term"><em class="replaceable"><code>value</code></em></span></dt><dd><p>
 112         Add or change the assignment to be made to a configuration parameter
 113         when the function is called.  If
 114         <em class="replaceable"><code>value</code></em> is <code class="literal">DEFAULT</code>
 115         or, equivalently, <code class="literal">RESET</code> is used, the function-local
 116         setting is removed, so that the function executes with the value
 117         present in its environment.  Use <code class="literal">RESET
 118         ALL</code> to clear all function-local settings.
 119         <code class="literal">SET FROM CURRENT</code> saves the value of the parameter that
 120         is current when <code class="command">ALTER FUNCTION</code> is executed as the value
 121         to be applied when the function is entered.
 122        </p><p>
 123         See <a class="xref" href="sql-set.html" title="SET"><span class="refentrytitle">SET</span></a> and
 124         <a class="xref" href="runtime-config.html" title="Chapter 19. Server Configuration">Chapter 19</a>
 125         for more information about allowed parameter names and values.
 126        </p></dd><dt><span class="term"><code class="literal">RESTRICT</code></span></dt><dd><p>
 127       Ignored for conformance with the SQL standard.
 128      </p></dd></dl></div></div><div class="refsect1" id="id-1.9.3.14.7"><h2>Examples</h2><p>
 129    To rename the function <code class="literal">sqrt</code> for type
 130    <code class="type">integer</code> to <code class="literal">square_root</code>:
 131 </p><pre class="programlisting">
 132 ALTER FUNCTION sqrt(integer) RENAME TO square_root;
 133 </pre><p>
 134   </p><p>
 135    To change the owner of the function <code class="literal">sqrt</code> for type
 136    <code class="type">integer</code> to <code class="literal">joe</code>:
 137 </p><pre class="programlisting">
 138 ALTER FUNCTION sqrt(integer) OWNER TO joe;
 139 </pre><p>
 140   </p><p>
 141    To change the schema of the function <code class="literal">sqrt</code> for type
 142    <code class="type">integer</code> to <code class="literal">maths</code>:
 143 </p><pre class="programlisting">
 144 ALTER FUNCTION sqrt(integer) SET SCHEMA maths;
 145 </pre><p>
 146   </p><p>
 147    To mark the function <code class="literal">sqrt</code> for type
 148    <code class="type">integer</code> as being dependent on the extension
 149    <code class="literal">mathlib</code>:
 150 </p><pre class="programlisting">
 151 ALTER FUNCTION sqrt(integer) DEPENDS ON EXTENSION mathlib;
 152 </pre><p>
 153   </p><p>
 154    To adjust the search path that is automatically set for a function:
 155 </p><pre class="programlisting">
 156 ALTER FUNCTION check_password(text) SET search_path = admin, pg_temp;
 157 </pre><p>
 158   </p><p>
 159    To disable automatic setting of <code class="varname">search_path</code> for a function:
 160 </p><pre class="programlisting">
 161 ALTER FUNCTION check_password(text) RESET search_path;
 162 </pre><p>
 163    The function will now execute with whatever search path is used by its
 164    caller.
 165   </p></div><div class="refsect1" id="id-1.9.3.14.8"><h2>Compatibility</h2><p>
 166    This statement is partially compatible with the <code class="command">ALTER
 167    FUNCTION</code> statement in the SQL standard. The standard allows more
 168    properties of a function to be modified, but does not provide the
 169    ability to rename a function, make a function a security definer,
 170    attach configuration parameter values to a function,
 171    or change the owner, schema, or volatility of a function. The standard also
 172    requires the <code class="literal">RESTRICT</code> key word, which is optional in
 173    <span class="productname">PostgreSQL</span>.
 174   </p></div><div class="refsect1" id="id-1.9.3.14.9"><h2>See Also</h2><span class="simplelist"><a class="xref" href="sql-createfunction.html" title="CREATE FUNCTION"><span class="refentrytitle">CREATE FUNCTION</span></a>, <a class="xref" href="sql-dropfunction.html" title="DROP FUNCTION"><span class="refentrytitle">DROP FUNCTION</span></a>, <a class="xref" href="sql-alterprocedure.html" title="ALTER PROCEDURE"><span class="refentrytitle">ALTER PROCEDURE</span></a>, <a class="xref" href="sql-alterroutine.html" title="ALTER ROUTINE"><span class="refentrytitle">ALTER ROUTINE</span></a></span></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="sql-alterforeigntable.html" title="ALTER FOREIGN TABLE">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="sql-commands.html" title="SQL Commands">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="sql-altergroup.html" title="ALTER GROUP">Next</a></td></tr><tr><td width="40%" align="left" valign="top">ALTER FOREIGN TABLE </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 18.0 Documentation">Home</a></td><td width="40%" align="right" valign="top"> ALTER GROUP</td></tr></table></div></body></html>