doc/src/sgml/ref/drop_statistics.sgml - master - githubmirror/postgres

doc/src/sgml/ref/drop_statistics.sgml
108 строк2 KB
Michael Paquier
doc: Mention CASCADE/RESTRICT for DROP STATISTICS
19 июл 2021, 06:39
19 июл 2021, 06:39d121663
<!--
doc/src/sgml/ref/drop_statistics.sgml
PostgreSQL documentation
-->

<refentry id="sql-dropstatistics">
 <indexterm zone="sql-dropstatistics">
  <primary>DROP STATISTICS</primary>
 </indexterm>

 <refmeta>
  <refentrytitle>DROP STATISTICS</refentrytitle>
  <manvolnum>7</manvolnum>
  <refmiscinfo>SQL - Language Statements</refmiscinfo>
 </refmeta>

 <refnamediv>
  <refname>DROP STATISTICS</refname>
  <refpurpose>remove extended statistics</refpurpose>
 </refnamediv>

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

 <refsect1>
  <title>Description</title>

  <para>
   <command>DROP STATISTICS</command> removes statistics object(s) from the
   database.  Only the statistics object's owner, the schema owner, or a
   superuser can drop a statistics object.
  </para>

 </refsect1>

 <refsect1>
  <title>Parameters</title>

  <variablelist>
   <varlistentry>
    <term><literal>IF EXISTS</literal></term>
    <listitem>
     <para>
      Do not throw an error if the statistics object 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 the statistics object to drop.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><literal>CASCADE</literal></term>
    <term><literal>RESTRICT</literal></term>

    <listitem>
     <para>
      These key words do not have any effect, since there are no dependencies
      on statistics.
     </para>
    </listitem>
   </varlistentry>

  </variablelist>
 </refsect1>

 <refsect1>
  <title>Examples</title>

  <para>
   To destroy two statistics objects in different schemas, without failing
   if they don't exist:

<programlisting>
DROP STATISTICS IF EXISTS
    accounting.users_uid_creation,
    public.grants_user_role;
</programlisting></para>
 </refsect1>

 <refsect1>
  <title>Compatibility</title>

  <para>
   There is no <command>DROP STATISTICS</command> command in the SQL standard.
  </para>
 </refsect1>

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

  <simplelist type="inline">
   <member><xref linkend="sql-alterstatistics"/></member>
   <member><xref linkend="sql-createstatistics"/></member>
  </simplelist>
 </refsect1>

</refentry>