The following table shows when SQL statements are allowed depending on the Teradata Database or table state.
| Teradata Database or Table State | Read Requests | Write Requests |
|---|---|---|
| Active | Yes | Yes |
| Read-Only | Yes | No |
| Standby | No (as long as there is another Active copy of the table or system) | Yes |
| Out-of-Service | No | No |
| Disconnected | No | No |
| Interrupted | No | No |
| Restore | No | No |
| Unrecoverable | No | No |
Write requests are rejected if there are no systems where the table is in an Active or Standby state.