role="catalog_table_entry"><para role="column_definition">
       <structfield>scope_name</structfield> <type>sql_identifier</type>
      </para>
      <para>
       Applies to a feature not available in <productname>PostgreSQL</productname>
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>maximum_cardinality</structfield> <type>cardinal_number</type>
      </para>
      <para>
       Always null, because arrays always have unlimited maximum cardinality in <productname>PostgreSQL</productname>
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>dtd_identifier</structfield> <type>sql_identifier</type>
      </para>
      <para>
       An identifier of the data type descriptor of the return data
       type of this function, unique among the data type descriptors
       pertaining to the function.  This is mainly useful for joining
       with other instances of such identifiers.  (The specific format
       of the identifier is not defined and not guaranteed to remain
       the same in future versions.)
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>routine_body</structfield> <type>character_data</type>
      </para>
      <para>
       If the function is an SQL function, then
       <literal>SQL</literal>, else <literal>EXTERNAL</literal>.
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>routine_definition</structfield> <type>character_data</type>
      </para>
      <para>
       The source text of the function (null if the function is not
       owned by a currently enabled role).  (According to the SQL
       standard, this column is only applicable if
       <literal>routine_body</literal> is <literal>SQL</literal>, but
       in <productname>PostgreSQL</productname> it will contain
       whatever source text was specified when the function was
       created.)
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>external_name</structfield> <type>character_data</type>
      </para>
      <para>
       If this function is a C function, then the external name (link
       symbol) of the function; else null.  (This works out to be the
       same value that is shown in
       <literal>routine_definition</literal>.)
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>external_language</structfield> <type>character_data</type>
      </para>
      <para>
       The language the function is written in
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>parameter_style</structfield> <type>character_data</type>
      </para>
      <para>
       Always <literal>GENERAL</literal> (The SQL standard defines
       other parameter styles, which are not available in <productname>PostgreSQL</productname>.)
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>is_deterministic</structfield> <type>yes_or_no</type>
      </para>
      <para>
       If the function is declared immutable (called deterministic in
       the SQL standard), then <literal>YES</literal>, else
       <literal>NO</literal>.  (You cannot query the other volatility
       levels available in <productname>PostgreSQL</productname> through the information schema.)
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>sql_data_access</structfield> <type>character_data</type>
      </para>
      <para>