DBA_TAB_COLUMNS¶
DBA_TAB_COLUMNS stores the columns of tables and views. Each column of a table in the database has a row in DBA_TAB_COLUMNS. Only users with system administrator permissions can access this view.
Column | Type | Description |
|---|---|---|
owner | character varying(64) | Owner of a table/view |
table_name | character varying(64) | Table/View name |
column_name | character varying(64) | Column name |
data_type | character varying(128) | Data type of the column |
column_id | Integer | Sequence number of the column when a table/view is created |
data_length | Integer | Length of the column, in bytes |
comments | Text | Comments |
avg_col_len | Numeric | Average length of a column, in bytes |
nullable | bpchar | Whether the column can be empty. For the primary key constraint and non-null constraint, the value is n. |
data_precision | Integer | Precision of the data type. This parameter is valid for the numeric data type and NULL for other data types. |
data_scale | Integer | Number of decimal places. This parameter is valid for the numeric data type and 0 for other data types. |
char_length | Numeric | Length of a column, in characters. This parameter is valid only for the varchar, nvarchar2, bpchar, and char types. |
schema | character varying(64) | Namespace that contains the table or view. |
kind | Text | Type of the current record. If the column belongs to a table, the value of this column is table. If the column belongs to a view, the value of this column is view. |