---
title: "Reserved names"
url: "https://docs.yugabyte.com/stable/api/ysql/reserved_names/"
---

# Reserved names

List of YSQL system column and database object names that are reserved for internal usage.

YSQL reserves the following names for internal usage. Exception will be raised when these names are used even when they are double-quoted.

| Names               | Description             |
|---------------------|-------------------------|
| `oid`               | System column           |
| `tableoid`          | System column           |
| `xmin`              | System column           |
| `cmin`              | System column           |
| `xmax`              | System column           |
| `cmax`              | System column           |
| `ctid`              | System column           |
| `ybctid`            | Virtual column          |
| Prefixed with `pg_` | System database objects |
| Prefixed with `yb_` | System database objects |