DB_TAB_COLUMNS

DB_TAB_COLUMNS displays description information about columns of tables accessible to the current user. This view exists in both PG_CATALOG and SYS schema.

**Table 1** DB_TAB_COLUMNS columns
Name	Type	Description
owner	character varying(64)	Table owner
table_name	character varying(64)	Table name
column_name	character varying(64)	Column name
data_type	character varying(128)	Data type of a column
data_length	integer	Length of a column, in bytes
data_precision	integer	Precision of the data type. This parameter is valid for the numeric data type and is set to NULL for other data types.
data_scale	integer	Number of decimal places. This parameter is valid for the numeric data type and is set to 0 for other data types.
nullable	bpchar	Whether a column can be empty (n for the primary key constraint and non-null constraint)
column_id	integer	Column ID generated when an object is created or a column is added
char_length	numeric	Length of a column, in characters. This parameter is valid only for the varchar, nvarchar2, bpchar, and char types.
avg_col_len	numeric	Average length of a column, in bytes
comments	text	Comments