preceding per-element
       frequencies, and optionally the frequency of null elements.
       (Null when <structfield>most_common_elems</structfield> is.)
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>elem_count_histogram</structfield> <type>float4[]</type>
      </para>
      <para>
       A histogram of the counts of distinct non-null element values within the
       values of the expression, followed by the average number of distinct
       non-null elements.  (Null for scalar types.)
      </para></entry>
     </row>
    </tbody>
   </tgroup>
  </table>

  <para>
   The maximum number of entries in the array fields can be controlled on a
   column-by-column basis using the <link linkend="sql-altertable"><command>ALTER
   TABLE SET STATISTICS</command></link> command, or globally by setting the
   <xref linkend="guc-default-statistics-target"/> run-time parameter.
  </para>

 </sect1>

 <sect1 id="view-pg-tables">
  <title><structname>pg_tables</structname></title>

  <indexterm zone="view-pg-tables">
   <primary>pg_tables</primary>
  </indexterm>

  <para>
   The view <structname>pg_tables</structname> provides access to
   useful information about each table in the database.
  </para>

  <table>
   <title><structname>pg_tables</structname> Columns</title>
   <tgroup cols="1">
    <thead>
     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       Column Type
      </para>
      <para>
       Description
      </para></entry>
     </row>
    </thead>

    <tbody>
     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>schemaname</structfield> <type>name</type>
       (references <link linkend="catalog-pg-namespace"><structname>pg_namespace</structname></link>.<structfield>nspname</structfield>)
      </para>
      <para>
       Name of schema containing table
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>tablename</structfield> <type>name</type>
       (references <link linkend="catalog-pg-class"><structname>pg_class</structname></link>.<structfield>relname</structfield>)
      </para>
      <para>
       Name of table
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>tableowner</structfield> <type>name</type>
       (references <link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.<structfield>rolname</structfield>)
      </para>
      <para>
       Name of table's owner
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>tablespace</structfield> <type>name</type>
       (references <link linkend="catalog-pg-tablespace"><structname>pg_tablespace</structname></link>.<structfield>spcname</structfield>)
      </para>
      <para>
       Name of tablespace containing table (null if default for database)
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>hasindexes</structfield> <type>bool</type>
       (references <link linkend="catalog-pg-class"><structname>pg_class</structname></link>.<structfield>relhasindex</structfield>)
      </para>
      <para>
       True if table has (or recently had) any indexes
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>hasrules</structfield> <type>bool</type>
       (references <link linkend="catalog-pg-class"><structname>pg_class</structname></link>.<structfield>relhasrules</structfield>)
      </para>
      <para>
       True if table has (or once had) rules
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">