alter_aggregate.sgml

postgresql8.3.4源码,开源数据库

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<refentry id="SQL-ALTERAGGREGATE">
 <refmeta>
  <refentrytitle id="SQL-ALTERAGGREGATE-TITLE">ALTER AGGREGATE</refentrytitle>
  <refmiscinfo>SQL - Language Statements</refmiscinfo>
 </refmeta>

 <refnamediv>
  <refname>ALTER AGGREGATE</refname>
  <refpurpose>change the definition of an aggregate function</refpurpose>
 </refnamediv>  
  
 <indexterm zone="sql-alteraggregate">
  <primary>ALTER AGGREGATE</primary>
 </indexterm>

 <refsynopsisdiv>
<synopsis>
ALTER AGGREGATE <replaceable>name</replaceable> ( <replaceable>type</replaceable> [ , ... ] ) RENAME TO <replaceable>new_name</replaceable>
ALTER AGGREGATE <replaceable>name</replaceable> ( <replaceable>type</replaceable> [ , ... ] ) OWNER TO <replaceable>new_owner</replaceable>
ALTER AGGREGATE <replaceable>name</replaceable> ( <replaceable>type</replaceable> [ , ... ] ) SET SCHEMA <replaceable>new_schema</replaceable>
</synopsis>
 </refsynopsisdiv>
  
 <refsect1>
  <title>Description</title>

  <para>
   <command>ALTER AGGREGATE</command> changes the definition of an
   aggregate function.
  </para>

  <para>
   You must own the aggregate function to use <command>ALTER AGGREGATE</>.
   To change the schema of an aggregate function, you must also have
   <literal>CREATE</literal> privilege on the new schema.
   To alter the owner, you must also be a direct or indirect member of the new
   owning role, and that role must have <literal>CREATE</literal> privilege on
   the aggregate function's schema.  (These restrictions enforce that altering
   the owner doesn't do anything you couldn't do by dropping and recreating
   the aggregate function.  However, a superuser can alter ownership of any
   aggregate function anyway.)
  </para>
 </refsect1>
  
 <refsect1>
  <title>Parameters</title>

  <variablelist>
   <varlistentry>
    <term><replaceable class="parameter">name</replaceable></term>
    <listitem>
     <para>
      The name (optionally schema-qualified) of an existing aggregate function.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="parameter">type</replaceable></term>
    <listitem>
     <para>
      An input data type on which the aggregate function operates.
      To reference a zero-argument aggregate function, write <literal>*</>
      in place of the list of input data types.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="parameter">new_name</replaceable></term>
    <listitem>
     <para>
      The new name of the aggregate function.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="parameter">new_owner</replaceable></term>
    <listitem>
     <para>
      The new owner of the aggregate function.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="parameter">new_schema</replaceable></term>
    <listitem>
     <para>
      The new schema for the aggregate function.
     </para>
    </listitem>
   </varlistentry>
  </variablelist>
 </refsect1>

 <refsect1>
  <title>Examples</title>

  <para>
   To rename the aggregate function <literal>myavg</literal> for type
   <type>integer</type> to <literal>my_average</literal>:
<programlisting>
ALTER AGGREGATE myavg(integer) RENAME TO my_average;
</programlisting>
  </para>

  <para>
   To change the owner of the aggregate function <literal>myavg</literal> for type
   <type>integer</type> to <literal>joe</literal>:
<programlisting>
ALTER AGGREGATE myavg(integer) OWNER TO joe;
</programlisting>
  </para>

  <para>
   To move the aggregate function <literal>myavg</literal> for type
   <type>integer</type> into schema <literal>myschema</literal>:
<programlisting>
ALTER AGGREGATE myavg(integer) SET SCHEMA myschema;
</programlisting>
  </para>
 </refsect1>

 <refsect1>
  <title>Compatibility</title>

  <para>
   There is no <command>ALTER AGGREGATE</command> statement in the SQL
   standard.
  </para>
 </refsect1>

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

  <simplelist type="inline">
   <member><xref linkend="sql-createaggregate" endterm="sql-createaggregate-title"></member>
   <member><xref linkend="sql-dropaggregate" endterm="sql-dropaggregate-title"></member>
  </simplelist>
 </refsect1>
</refentry>