# pg_exttable

The `pg_exttable` system catalog table is used to track external tables and web tables created by the `CREATE EXTERNAL TABLE` command.



Table 1. `pg_catalog.pg_exttable`

| column            | type    | references            | description                                                  |
| :---------------- | :------ | :-------------------- | :----------------------------------------------------------- |
| `reloid`          | oid     | pg_class_internal.oid | The OID of this external table.                              |
| `location`        | text[]  |                       | The URI location(s) of the external table files.             |
| `fmttype`         | char    |                       | Format of the external table files: `t` for text, or `c` for csv. |
| `fmtopts`         | text    |                       | Formatting options of the external table files, such as the field delimiter, null string, escape character, etc. |
| `command`         | text    |                       | The OS command to execute when the external table is accessed. |
| `rejectlimit`     | integer |                       | The per segment reject limit for rows with errors, after which the load will fail. |
| `rejectlimittype` | char    |                       | Type of reject limit threshold: `r` for number of rows.      |
| `fmterrtbl`       | oid     | pg_class_internal.oid | The object id of the error table where format errors will be logged. |
| `encoding`        | text    |                       | The client encoding.                                         |
| `writable`        | boolean |                       | `0` for readable external tables, `1` for writable external tables. |