| table_catalog | sql_identifier | Name of the database containing the table (always the current database) |
| table_schema | sql_identifier | Name of the schema containing the table |
| table_name | sql_identifier | Name of the table |
| column_name | sql_identifier | Name of the column |
| ordinal_position | cardinal_number | Ordinal position of the column within the table (count starts at 1) |
| column_default | character_data | Default expression of the column |
| is_nullable | yes_or_no | YES if the column is possibly nullable,
NO if it is known not nullable. A not-null
constraint is one way a column can be known not nullable, but
there can be others.
|
| data_type | character_data | Data type of the column, if it is a built-in type, or
ARRAY if it is some array (in that case, see
the view element_types), else
USER-DEFINED (in that case, the type is
identified in udt_name and associated
columns). If the column is based on a domain, this column
refers to the type underlying the domain (and the domain is
identified in domain_name and associated
columns).
|
| character_maximum_length | cardinal_number | If data_type identifies 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_type identifies 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.
|
| numeric_precision | cardinal_number | If data_type identifies a numeric type, this
column contains the (declared or implicit) precision of the
type for this column. 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 column
numeric_precision_radix. For all other data
types, this column is null.
|
| numeric_precision_radix | cardinal_number | If data_type identifies a numeric type, this
column indicates in which base the values in the columns
numeric_precision and
numeric_scale are expressed. The value is
either 2 or 10. For all other data types, this column is null.
|
| numeric_scale | cardinal_number | If data_type identifies an exact numeric
type, this column contains the (declared or implicit) scale of
the type for this column. 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 column
numeric_precision_radix. For all other data
types, this column is null.
|
| datetime_precision | cardinal_number | If data_type identifies a date, time,
timestamp, or interval type, this column contains the (declared
or implicit) fractional seconds precision of the type for this
column, 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 | Not yet implemented |
| interval_precision | character_data | Not yet implemented |
| 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 | Not yet implemented |
| collation_schema | sql_identifier | Not yet implemented |
| collation_name | sql_identifier | Not yet implemented |
| domain_catalog | sql_identifier | If the column has a domain type, the name of the database that
the domain is defined in (always the current database), else
null.
|
| domain_schema | sql_identifier | If the column has a domain type, the name of the schema that
the domain is defined in, else null.
|
| domain_name | sql_identifier | If the column has a domain type, the name of the domain, else null. |
| udt_catalog | sql_identifier | Name of the database that the column data type (the underlying
type of the domain, if applicable) is defined in (always the
current database)
|
| udt_schema | sql_identifier | Name of the schema that the column data type (the underlying
type of the domain, if applicable) is defined in
|
| udt_name | sql_identifier | Name of the column data type (the underlying type of the
domain, if applicable)
|
| 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 column, unique
among the data type descriptors pertaining to the table. 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_self_referencing | yes_or_no | Applies to a feature not available in PostgreSQL |
| is_identity | yes_or_no | Applies to a feature not available in PostgreSQL |
| identity_generation | character_data | Applies to a feature not available in PostgreSQL |
| identity_start | character_data | Applies to a feature not available in PostgreSQL |
| identity_increment | character_data | Applies to a feature not available in PostgreSQL |
| identity_maximum | character_data | Applies to a feature not available in PostgreSQL |
| identity_minimum | character_data | Applies to a feature not available in PostgreSQL |
| identity_cycle | yes_or_no | Applies to a feature not available in PostgreSQL |
| is_generated | character_data | Applies to a feature not available in PostgreSQL |
| generation_expression | character_data | Applies to a feature not available in PostgreSQL |
| is_updatable | yes_or_no | YES if the column is updatable,
NO if not (Columns in base tables are always
updatable, columns in views not necessarily)
|