# Request limits

Request limits bound one SQL request, including its statements. Configure a server ceiling in XML or save a tighter value for the selected database with SET.

## Limits

| Setting              | Unit                                                                  |
| -------------------- | --------------------------------------------------------------------- |
| `max_execution_time` | Seconds.                                                              |
| `max_memory_usage`   | Bytes of accounted query memory.                                      |
| `max_result_rows`    | Returned rows accumulated across the request.                         |
| `max_response_bytes` | Encoded successful response bytes, including logical protocol fields. |

All default to zero, meaning no added ceiling at that level. The stricter nonzero server and database values apply.

## Results and errors

Returned rows include the result-bearing statements covered by the request contract. Response-byte limits count encoded output and protocol fields, rather than only cell values. The protocol independently caps a response at 16 MiB.

Exceeding a limit returns a database error. Transaction recovery commands remain available so the client can finish or roll back its transaction.

Use [`system.settings`](https://coordinatordb.com/docs/reference/system-tables/settings) to inspect effective values and [`system.query_log`](https://coordinatordb.com/docs/reference/system-tables/query-log) for completed request metrics. See the [database settings reference](https://coordinatordb.com/docs/reference/settings/session-settings) for each setting's exact accounting scope.