ADM_TAB_COLS

ADM_TAB_COLS displays information about table and view columns. Each column of each table and view in the database has a row of data in ADM_TAB_COLS. By default, only the system administrator can access this view. Common users can access the view only after being authorized. This view exists in the PG_CATALOG and SYS schemas. The number of rows displayed in this view is the same as that in the ADM_TAB_COLUMNS. Only columns are different.

**Table 1** ADM_TAB_COLS columns
Name	Type	Description
owner	character varying(64)	Owner of a table or view.
table_name	character varying(128)	Name of a table or view.
column_name	character varying(128)	Column name.
data_type	character varying(128)	Data type of a column, which can be a user-defined data type.
data_type_mod	character varying(3)	Not supported. Its value is NULL.
data_type_owner	character varying(128)	Owner of the data type of a column.
data_length	numeric	Length of a column, in bytes.
data_precision	numeric	Precision of the data type. It is valid for the numeric data type and NULL for other types.
data_scale	numeric	Number of decimal places. It is valid for the numeric data type and 0 for other data types.
nullable	character varying(1)	Specifies whether the column can be null. For primary key constraints and NOT NULL constraints, the value is n.
column_id	numeric	Sequence number of a column when the table is created.
default_length	numeric	Length of the default value of a column, in bytes.
data_default	text	Default value of a column.
num_distinct	numeric	Number of different values in a column.
low_value	raw	Minimum value in a column.
high_value	raw	Maximum value in a column.
density	numeric	Column density.
num_nulls	numeric	Number of empty values in a column.
num_buckets	numeric	Number of buckets in the histogram of a column.
last_analyzed	date	Last analysis date.
sample_size	numeric	Sample size used to analyze a column.
character_set_name	character varying(44)	Not supported. Its value is NULL.
char_col_decl_length	numeric	Declaration length of a column of the character type.
global_stats	character varying(3)	Not supported. The value is NO.
user_stats	character varying(3)	Not supported. The value is NO.
avg_col_len	numeric	Average length of a column, in bytes.
char_length	numeric	Column length (in bytes) which is valid only for the varchar, nvarchar2, bpchar, and char types.
char_used	character varying(1)	Not supported currently. B: varchar, nvarchar2, bpchar, and char. NULL: other types.
v80_fmt_image	character varying(3)	Not supported. Its value is NULL.
data_upgraded	character varying(3)	Not supported. The value is YES.
hidden_column	character varying(3)	Not supported. Its value is NULL.
virtual_column	character varying	Specifies whether a column is a virtual column (a generated column). YES: yes. NO: no.
segment_column_id	numeric	Not supported. Its value is NULL.
internal_column_id	numeric	Internal sequence number of a column. The value is the same as that of COLUMN_ID.
histogram	character varying(15)	Specifies whether the histogram exists and the type of the histogram. NONE: no histogram. FREQUENCY: frequency histogram. EQUI_WIDTH: equal-width histogram.
qualified_col_name	character varying(64)	Qualified column name, which is the same as COLUMN_NAME.
user_generated	character varying(3)	Not supported. The value is YES.
default_on_null	character varying(3)	Not supported. Its value is NULL.
identity_column	character varying(3)	Not supported. Its value is NULL.
sensitive_column	character varying(3)	Not supported. Its value is NULL.
evaluation_edition	character varying(128)	Not supported. Its value is NULL.
unusable_before	character varying(128)	Not supported. Its value is NULL.
unusable_beginning	character varying(128)	Not supported. Its value is NULL.
collation	character varying(100)	Collation rule of a column. This column conflicts with reserved keywords. Therefore, add the view name when calling this column.
collated_column_id	numeric	Not supported. Its value is NULL.
schema	character varying(64)	Name of the namespace to which the column belongs.