attributes
   The view attributes contains information about
   the attributes of composite data types defined in the database.
   (Note that the view does not give information about table columns,
   which are sometimes called attributes in PostgreSQL contexts.)
   Only those attributes are shown that the current user has access to (by way
   of being the owner of or having some privilege on the type).
  
Table 36.4. attributes Columns
| Name | Data Type | Description | 
|---|---|---|
| udt_catalog | sql_identifier | Name of the database containing the data type (always the current database) | 
| udt_schema | sql_identifier | Name of the schema containing the data type | 
| udt_name | sql_identifier | Name of the data type | 
| attribute_name | sql_identifier | Name of the attribute | 
| ordinal_position | cardinal_number | Ordinal position of the attribute within the data type (count starts at 1) | 
| attribute_default | character_data | Default expression of the attribute | 
| is_nullable | yes_or_no | YESif the attribute is possibly nullable,NOif it is known not nullable. | 
| data_type | character_data | Data type of the attribute, if it is a built-in type, or ARRAYif it is some array (in that case, see
       the viewelement_types), elseUSER-DEFINED(in that case, the type is
       identified inattribute_udt_nameand
       associated columns). | 
| character_maximum_length | cardinal_number | If data_typeidentifies a character or bit
       string type, the declared maximum length; null for all other
       data types or if no maximum length was declared. | 
| character_octet_length | cardinal_number | If data_typeidentifies a character type,
       the maximum possible length in octets (bytes) of a datum; null
       for all other data types.  The maximum octet length depends on
       the declared character maximum length (see above) and the
       server encoding. | 
| character_set_catalog | sql_identifier | Applies to a feature not available in PostgreSQL | 
| character_set_schema | sql_identifier | Applies to a feature not available in PostgreSQL | 
| character_set_name | sql_identifier | Applies to a feature not available in PostgreSQL | 
| collation_catalog | sql_identifier | Name of the database containing the collation of the attribute (always the current database), null if default or the data type of the attribute is not collatable | 
| collation_schema | sql_identifier | Name of the schema containing the collation of the attribute, null if default or the data type of the attribute is not collatable | 
| collation_name | sql_identifier | Name of the collation of the attribute, null if default or the data type of the attribute is not collatable | 
| numeric_precision | cardinal_number | If data_typeidentifies a numeric type, this
       column contains the (declared or implicit) precision of the
       type for this attribute.  The precision indicates the number of
       significant digits.  It can be expressed in decimal (base 10)
       or binary (base 2) terms, as specified in the columnnumeric_precision_radix.  For all other data
       types, this column is null. | 
| numeric_precision_radix | cardinal_number | If data_typeidentifies a numeric type, this
       column indicates in which base the values in the columnsnumeric_precisionandnumeric_scaleare expressed.  The value is
       either 2 or 10.  For all other data types, this column is null. | 
| numeric_scale | cardinal_number | If data_typeidentifies an exact numeric
       type, this column contains the (declared or implicit) scale of
       the type for this attribute.  The scale indicates the number of
       significant digits to the right of the decimal point.  It can
       be expressed in decimal (base 10) or binary (base 2) terms, as
       specified in the columnnumeric_precision_radix.  For all other data
       types, this column is null. | 
| datetime_precision | cardinal_number | If data_typeidentifies a date, time,
       timestamp, or interval type, this column contains the (declared
       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. | 
| interval_type | character_data | If data_typeidentifies an interval type,
       this column contains the specification which fields the
       intervals include for this attribute, e.g.,YEAR TO
       MONTH,DAY TO SECOND, etc.  If no
       field restrictions were specified (that is, the interval
       accepts all fields), and for all other data types, this field
       is null. | 
| interval_precision | cardinal_number | Applies to a feature not available
       in PostgreSQL
       (see datetime_precisionfor the fractional
       seconds precision of interval type attributes) | 
| attribute_udt_catalog | sql_identifier | Name of the database that the attribute data type is defined in (always the current database) | 
| attribute_udt_schema | sql_identifier | Name of the schema that the attribute data type is defined in | 
| attribute_udt_name | sql_identifier | Name of the attribute data type | 
| scope_catalog | sql_identifier | Applies to a feature not available in PostgreSQL | 
| scope_schema | sql_identifier | Applies to a feature not available in PostgreSQL | 
| scope_name | sql_identifier | Applies to a feature not available in PostgreSQL | 
| maximum_cardinality | cardinal_number | Always null, because arrays always have unlimited maximum cardinality in PostgreSQL | 
| dtd_identifier | sql_identifier | 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 not guaranteed to remain the same in future versions.) | 
| is_derived_reference_attribute | yes_or_no | Applies to a feature not available in PostgreSQL | 
See also under Section 36.17, a similarly structured view, for further information on some of the columns.