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<?xml version="1.0" encoding="UTF-8" standalone="no"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>ALTER FUNCTION</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@lists.postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><link rel="prev" href="sql-alterforeigntable.html" title="ALTER FOREIGN TABLE" /><link rel="next" href="sql-altergroup.html" title="ALTER GROUP" /></head><body id="docContent" class="container-fluid col-10"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">ALTER FUNCTION</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="sql-alterforeigntable.html" title="ALTER FOREIGN TABLE">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="sql-commands.html" title="SQL Commands">Up</a></td><th width="60%" align="center">SQL Commands</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 16.3 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="sql-altergroup.html" title="ALTER GROUP">Next</a></td></tr></table><hr /></div><div class="refentry" id="SQL-ALTERFUNCTION"><div class="titlepage"></div><a id="id-1.9.3.14.1" class="indexterm"></a><div class="refnamediv"><h2><span class="refentrytitle">ALTER FUNCTION</span></h2><p>ALTER FUNCTION — change the definition of a function</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><pre class="synopsis"> 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> [, ...] ] ) ] <em class="replaceable"><code>action</code></em> [ ... ] [ RESTRICT ] 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> [, ...] ] ) ] RENAME TO <em class="replaceable"><code>new_name</code></em> 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> [, ...] ] ) ] OWNER TO { <em class="replaceable"><code>new_owner</code></em> | CURRENT_ROLE | CURRENT_USER | SESSION_USER } 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> [, ...] ] ) ] SET SCHEMA <em class="replaceable"><code>new_schema</code></em> 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> [, ...] ] ) ] [ NO ] DEPENDS ON EXTENSION <em class="replaceable"><code>extension_name</code></em> <span class="phrase">where <em class="replaceable"><code>action</code></em> is one of:</span> CALLED ON NULL INPUT | RETURNS NULL ON NULL INPUT | STRICT IMMUTABLE | STABLE | VOLATILE [ NOT ] LEAKPROOF [ EXTERNAL ] SECURITY INVOKER | [ EXTERNAL ] SECURITY DEFINER PARALLEL { UNSAFE | RESTRICTED | SAFE } COST <em class="replaceable"><code>execution_cost</code></em> ROWS <em class="replaceable"><code>result_rows</code></em> SUPPORT <em class="replaceable"><code>support_function</code></em> SET <em class="replaceable"><code>configuration_parameter</code></em> { TO | = } { <em class="replaceable"><code>value</code></em> | DEFAULT } SET <em class="replaceable"><code>configuration_parameter</code></em> FROM CURRENT RESET <em class="replaceable"><code>configuration_parameter</code></em> RESET ALL </pre></div><div class="refsect1" id="id-1.9.3.14.5"><h2>Description</h2><p> <code class="command">ALTER FUNCTION</code> changes the definition of a function. </p><p> You must own the function to use <code class="command">ALTER FUNCTION</code>. To change a function's schema, you must also have <code class="literal">CREATE</code> privilege on the new schema. To alter the owner, you must be able to <code class="literal">SET ROLE</code> to the new owning role, and that role must have <code class="literal">CREATE</code> privilege on the function's schema. (These restrictions enforce that altering the owner doesn't do anything you couldn't do by dropping and recreating the function. However, a superuser can alter ownership of any function anyway.) </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> The name (optionally schema-qualified) of an existing function. If no argument list is specified, the name must be unique in its schema. </p></dd><dt><span class="term"><em class="replaceable"><code>argmode</code></em></span></dt><dd><p> The mode of an argument: <code class="literal">IN</code>, <code class="literal">OUT</code>, <code class="literal">INOUT</code>, or <code class="literal">VARIADIC</code>. If omitted, the default is <code class="literal">IN</code>. Note that <code class="command">ALTER FUNCTION</code> does not actually pay any attention to <code class="literal">OUT</code> arguments, since only the input arguments are needed to determine the function's identity. So it is sufficient to list the <code class="literal">IN</code>, <code class="literal">INOUT</code>, and <code class="literal">VARIADIC</code> arguments. </p></dd><dt><span class="term"><em class="replaceable"><code>argname</code></em></span></dt><dd><p> The name of an argument. Note that <code class="command">ALTER FUNCTION</code> does not actually pay any attention to argument names, since only the argument data types are needed to determine the function's identity. </p></dd><dt><span class="term"><em class="replaceable"><code>argtype</code></em></span></dt><dd><p> The data type(s) of the function's arguments (optionally schema-qualified), if any. </p></dd><dt><span class="term"><em class="replaceable"><code>new_name</code></em></span></dt><dd><p> The new name of the function. </p></dd><dt><span class="term"><em class="replaceable"><code>new_owner</code></em></span></dt><dd><p> The new owner of the function. Note that if the function is marked <code class="literal">SECURITY DEFINER</code>, it will subsequently execute as the new owner. </p></dd><dt><span class="term"><em class="replaceable"><code>new_schema</code></em></span></dt><dd><p> The new schema for the function. </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> This form marks the function as dependent on the extension, or no longer dependent on that extension if <code class="literal">NO</code> is specified. A function that's marked as dependent on an extension is dropped when the extension is dropped, even if <code class="literal">CASCADE</code> is not specified. A function can depend upon multiple extensions, and will be dropped when any one of those extensions is dropped. </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 that it will be invoked when some or all of its arguments are null. <code class="literal">RETURNS NULL ON NULL INPUT</code> or <code class="literal">STRICT</code> changes the function so that it is not invoked if any of its arguments are null; instead, a null result is assumed automatically. See <a class="xref" href="sql-createfunction.html" title="CREATE FUNCTION"><span class="refentrytitle">CREATE FUNCTION</span></a> for more information. </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> Change the volatility of the function to the specified setting. See <a class="xref" href="sql-createfunction.html" title="CREATE FUNCTION"><span class="refentrytitle">CREATE FUNCTION</span></a> for details. </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> Change whether the function is a security definer or not. The key word <code class="literal">EXTERNAL</code> is ignored for SQL conformance. See <a class="xref" href="sql-createfunction.html" title="CREATE FUNCTION"><span class="refentrytitle">CREATE FUNCTION</span></a> for more information about this capability. </p></dd><dt><span class="term"><code class="literal">PARALLEL</code></span></dt><dd><p> Change whether the function is deemed safe for parallelism. See <a class="xref" href="sql-createfunction.html" title="CREATE FUNCTION"><span class="refentrytitle">CREATE FUNCTION</span></a> for details. </p></dd><dt><span class="term"><code class="literal">LEAKPROOF</code></span></dt><dd><p> Change whether the function is considered leakproof or not. See <a class="xref" href="sql-createfunction.html" title="CREATE FUNCTION"><span class="refentrytitle">CREATE FUNCTION</span></a> for more information about this capability. </p></dd><dt><span class="term"><code class="literal">COST</code> <em class="replaceable"><code>execution_cost</code></em></span></dt><dd><p> Change the estimated execution cost of the function. See <a class="xref" href="sql-createfunction.html" title="CREATE FUNCTION"><span class="refentrytitle">CREATE FUNCTION</span></a> for more information. </p></dd><dt><span class="term"><code class="literal">ROWS</code> <em class="replaceable"><code>result_rows</code></em></span></dt><dd><p> Change the estimated number of rows returned by a set-returning function. See <a class="xref" href="sql-createfunction.html" title="CREATE FUNCTION"><span class="refentrytitle">CREATE FUNCTION</span></a> for more information. </p></dd><dt><span class="term"><code class="literal">SUPPORT</code> <em class="replaceable"><code>support_function</code></em></span></dt><dd><p> Set or change the planner support function to use for this function. See <a class="xref" href="xfunc-optimization.html" title="38.11. Function Optimization Information">Section 38.11</a> for details. You must be superuser to use this option. </p><p> This option cannot be used to remove the support function altogether, since it must name a new support function. Use <code class="command">CREATE OR REPLACE FUNCTION</code> if you need to do that. </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> Add or change the assignment to be made to a configuration parameter when the function is called. If <em class="replaceable"><code>value</code></em> is <code class="literal">DEFAULT</code> or, equivalently, <code class="literal">RESET</code> is used, the function-local setting is removed, so that the function executes with the value present in its environment. Use <code class="literal">RESET ALL</code> to clear all function-local settings. <code class="literal">SET FROM CURRENT</code> saves the value of the parameter that is current when <code class="command">ALTER FUNCTION</code> is executed as the value to be applied when the function is entered. </p><p> See <a class="xref" href="sql-set.html" title="SET"><span class="refentrytitle">SET</span></a> and <a class="xref" href="runtime-config.html" title="Chapter 20. Server Configuration">Chapter 20</a> for more information about allowed parameter names and values. </p></dd><dt><span class="term"><code class="literal">RESTRICT</code></span></dt><dd><p> Ignored for conformance with the SQL standard. </p></dd></dl></div></div><div class="refsect1" id="id-1.9.3.14.7"><h2>Examples</h2><p> To rename the function <code class="literal">sqrt</code> for type <code class="type">integer</code> to <code class="literal">square_root</code>: </p><pre class="programlisting"> ALTER FUNCTION sqrt(integer) RENAME TO square_root; </pre><p> </p><p> To change the owner of the function <code class="literal">sqrt</code> for type <code class="type">integer</code> to <code class="literal">joe</code>: </p><pre class="programlisting"> ALTER FUNCTION sqrt(integer) OWNER TO joe; </pre><p> </p><p> To change the schema of the function <code class="literal">sqrt</code> for type <code class="type">integer</code> to <code class="literal">maths</code>: </p><pre class="programlisting"> ALTER FUNCTION sqrt(integer) SET SCHEMA maths; </pre><p> </p><p> To mark the function <code class="literal">sqrt</code> for type <code class="type">integer</code> as being dependent on the extension <code class="literal">mathlib</code>: </p><pre class="programlisting"> ALTER FUNCTION sqrt(integer) DEPENDS ON EXTENSION mathlib; </pre><p> </p><p> To adjust the search path that is automatically set for a function: </p><pre class="programlisting"> ALTER FUNCTION check_password(text) SET search_path = admin, pg_temp; </pre><p> </p><p> To disable automatic setting of <code class="varname">search_path</code> for a function: </p><pre class="programlisting"> ALTER FUNCTION check_password(text) RESET search_path; </pre><p> The function will now execute with whatever search path is used by its caller. </p></div><div class="refsect1" id="id-1.9.3.14.8"><h2>Compatibility</h2><p> This statement is partially compatible with the <code class="command">ALTER FUNCTION</code> statement in the SQL standard. The standard allows more properties of a function to be modified, but does not provide the ability to rename a function, make a function a security definer, attach configuration parameter values to a function, or change the owner, schema, or volatility of a function. The standard also requires the <code class="literal">RESTRICT</code> key word, which is optional in <span class="productname">PostgreSQL</span>. </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 16.3 Documentation">Home</a></td><td width="40%" align="right" valign="top"> ALTER GROUP</td></tr></table></div></body></html>