role="catalog_table_entry"><para role="column_definition">
       <structfield>comments</structfield> <type>character_data</type>
      </para>
      <para>
       Possibly a comment about the supported status of the feature
      </para></entry>
     </row>
    </tbody>
   </tgroup>
  </table>
 </sect1>

 <sect1 id="infoschema-sql-implementation-info">
  <title><literal>sql_implementation_info</literal></title>

  <para>
   The table <literal>sql_implementation_info</literal> contains
   information about various aspects that are left
   implementation-defined by the SQL standard.  This information is
   primarily intended for use in the context of the ODBC interface;
   users of other interfaces will probably find this information to be
   of little use.  For this reason, the individual implementation
   information items are not described here; you will find them in the
   description of the ODBC interface.
  </para>

  <table>
   <title><structname>sql_implementation_info</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>implementation_info_id</structfield> <type>character_data</type>
      </para>
      <para>
       Identifier string of the implementation information item
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>implementation_info_name</structfield> <type>character_data</type>
      </para>
      <para>
       Descriptive name of the implementation information item
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>integer_value</structfield> <type>cardinal_number</type>
      </para>
      <para>
       Value of the implementation information item, or null if the
       value is contained in the column
       <literal>character_value</literal>
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>character_value</structfield> <type>character_data</type>
      </para>
      <para>
       Value of the implementation information item, or null if the
       value is contained in the column
       <literal>integer_value</literal>
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>comments</structfield> <type>character_data</type>
      </para>
      <para>
       Possibly a comment pertaining to the implementation information item
      </para></entry>
     </row>
    </tbody>
   </tgroup>
  </table>
 </sect1>

 <sect1 id="infoschema-sql-parts">
  <title><literal>sql_parts</literal></title>

  <para>
   The table <literal>sql_parts</literal> contains information about
   which of the several parts of the SQL standard are supported by
   <productname>PostgreSQL</productname>.
  </para>

  <table>
   <title><structname>sql_parts</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>feature_id</structfield> <type>character_data</type>
      </para>
      <para>
       An identifier string containing the number of the part
      </para></entry>
     </row>

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