code: public ResultSet getSuperTables(String catalog, String schemaPattern, String tableNamePattern)
        throws SQLException {
      String sql =
          "SELECT  ' ' TABLE_CAT, ' ' TABLE_SCHEM, ' ' TABLE_NAME, ' ' SUPERTABLE_NAME FROM DUAL WHERE 1=0";
      return executeQuery(sql);
    }
docs: Retrieves a description of the table hierarchies defined in a particular schema in this
  database.
  
  <P>Only supertable information for tables matching the catalog, schema and table name are
  returned. The table name parameter may be a fully-qualified name, in which case, the catalog
  and schemaPattern parameters are ignored. If a table does not have a super table, it is not
  listed here. Supertables have to be defined in the same catalog and schema as the sub tables.
  Therefore, the type description does not need to include this information for the
  supertable.</p>
  
  <P>Each type description has the following columns:</p>
  <OL> <li><B>TABLE_CAT</B> String {@code
  =>} the type's catalog (may be <code>null</code>)
  <li><B>TABLE_SCHEM</B> String {@code =>} type's schema (may be <code>null</code>)
  <li><B>TABLE_NAME</B> String
  {@code =>} type name
  <li><B>SUPERTABLE_NAME</B> String {@code =>} the direct super type's name </OL>
  
  <P><B>Note:</B> If the driver does not support type hierarchies, an empty result set is
  returned.</p>
  
  @param catalog          a catalog name; "" retrieves those without a catalog; <code>null</code>
  means drop catalog name from the selection criteria
  @param schemaPattern    a schema name pattern; "" retrieves those without a schema
  @param tableNamePattern a table name pattern; may be a fully-qualified name
  @return a <code>ResultSet</code> object in which each row is a type description
  @throws SQLException if a database access error occurs
  @see #getSearchStringEscape
  @since 1.4