## 41.6. `pg_attrdef`

The catalog `pg_attrdef` stores column default values. The main information about columns is stored in `pg_attribute` (see below). Only columns that explicitly specify a default value (when the table is created or the column is added) will have an entry here.

Table 41.6. `pg_attrdef` Columns

Name | Type | References | Description
--- | --- | --- | ---
`adrelid` | `oid` | ``pg_class`.oid` | The table this column belongs to
`adnum` | `int2` | ``pg_attribute`.attnum` | The number of the column
`adbin` | `text` |  | The internal representation of the column default value
`adsrc` | `text` |  | A human-readable representation of the default value