or implicit) fractional seconds precision of the type for this
       attribute, that is, the number of decimal digits maintained
       following the decimal point in the seconds value.  For all
       other data types, this column is null.
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>interval_type</structfield> <type>character_data</type>
      </para>
      <para>
       If <literal>data_type</literal> identifies an interval type,
       this column contains the specification which fields the
       intervals include for this attribute, e.g., <literal>YEAR TO
       MONTH</literal>, <literal>DAY TO SECOND</literal>, etc.  If no
       field restrictions were specified (that is, the interval
       accepts all fields), and for all other data types, this field
       is null.
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>interval_precision</structfield> <type>cardinal_number</type>
      </para>
      <para>
       Applies to a feature not available
       in <productname>PostgreSQL</productname>
       (see <literal>datetime_precision</literal> for the fractional
       seconds precision of interval type attributes)
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>attribute_udt_catalog</structfield> <type>sql_identifier</type>
      </para>
      <para>
       Name of the database that the attribute data type is defined in
       (always the current database)
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>attribute_udt_schema</structfield> <type>sql_identifier</type>
      </para>
      <para>
       Name of the schema that the attribute data type is defined in
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>attribute_udt_name</structfield> <type>sql_identifier</type>
      </para>
      <para>
       Name of the attribute data type
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>scope_catalog</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>scope_schema</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>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 attribute, unique
       among the data type descriptors pertaining to the composite type.  This
       is mainly useful for joining with other instances of such
       identifiers.  (The specific format of the identifier is not
       defined and