drop_index.sgml

来自「postgresql8.3.4源码,开源数据库」· SGML 代码 · 共 112 行

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$PostgreSQL: pgsql/doc/src/sgml/ref/drop_index.sgml,v 1.23 2006/09/16 00:30:18 momjian Exp $
PostgreSQL documentation
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<refentry id="SQL-DROPINDEX">
 <refmeta>
  <refentrytitle id="SQL-DROPINDEX-TITLE">DROP INDEX</refentrytitle>
  <refmiscinfo>SQL - Language Statements</refmiscinfo>
 </refmeta>

 <refnamediv>
  <refname>DROP INDEX</refname>
  <refpurpose>remove an index</refpurpose>
 </refnamediv>

 <indexterm zone="sql-dropindex">
  <primary>DROP INDEX</primary>
 </indexterm>

 <refsynopsisdiv>
<synopsis>
DROP INDEX [ IF EXISTS ] <replaceable class="PARAMETER">name</replaceable> [, ...] [ CASCADE | RESTRICT ]
</synopsis>
 </refsynopsisdiv>

 <refsect1>
  <title>Description</title>

  <para>
   <command>DROP INDEX</command> drops an existing index from the database
   system. To execute this command you must be the owner of
   the index.
  </para>
 </refsect1>

 <refsect1>
  <title>Parameters</title>

  <variablelist>
   <varlistentry>
    <term><literal>IF EXISTS</literal></term>
    <listitem>
     <para>
      Do not throw an error if the index does not exist. A notice is issued 
      in this case.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="PARAMETER">name</replaceable></term>
    <listitem>
     <para>
      The name (optionally schema-qualified) of an index to remove.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><literal>CASCADE</literal></term>
    <listitem>
     <para>
      Automatically drop objects that depend on the index.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><literal>RESTRICT</literal></term>
    <listitem>
     <para>
      Refuse to drop the index if any objects depend on it.  This is
      the default.
     </para>
    </listitem>
   </varlistentry>
  </variablelist>
 </refsect1>

 <refsect1>
  <title>Examples</title>

  <para>
   This command will remove the index <literal>title_idx</literal>:

<programlisting>
DROP INDEX title_idx;
</programlisting>
  </para>
 </refsect1>

 <refsect1>
  <title>Compatibility</title>

  <para>
   <command>DROP INDEX</command> is a
   <productname>PostgreSQL</productname> language extension.  There
   are no provisions for indexes in the SQL standard.
  </para>
 </refsect1>

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

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

</refentry>