DB_TAB_COLUMNS

DB_TAB_COLUMNS displays description information about columns of tables and views 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 the column.
data_length	integer	Length of the column, in bytes.
data_precision	integer	Precision of a data type. This column is valid for the numeric data type and NULL for other data types.
data_scale	integer	Number of decimal places. This column is valid for the numeric data type and 0 for other data types.
nullable	bpchar	Specifies whether a column can be empty (n for a primary key constraint or NOT NULL constraint).
column_id	integer	Column ID generated when an object is created or a column is added.
char_length	numeric	Column length (in characters) which is valid only for varchar, nvarchar2, bpchar, and char types.
avg_col_len	numeric	Average length of a column, in bytes.
comments	text	Comments.