# Limits (/docs/using/data-api/limits)



## Request limits [#request-limits]

| Limit                                   | Value                                                                                                                                                                                               |
| --------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Request body                            | 1 MiB (413 `too_large`)                                                                                                                                                                             |
| Response                                | 16 MiB by default (`CHELABASE_REST_MAX_RESPONSE_BYTES` on `rest`). Each operation's result is counted as it arrives; the first one past the cap rolls the request back and answers 413 `too_large`. |
| Operations per batch                    | 50                                                                                                                                                                                                  |
| Alias (`{"col", "as"}`)                 | 1 to 63 bytes                                                                                                                                                                                       |
| Database name (`"database"`)            | 1 to 63 bytes                                                                                                                                                                                       |
| Rows                                    | The branch's `max_rows` [setting](/docs/using/data-api/settings)                                                                                                                                    |
| Gateway key lookups that miss the cache | 20 per second per client IP address (429 `rate_limited`)                                                                                                                                            |
| Databases a key may list                | 20                                                                                                                                                                                                  |
| Databases served per branch             | `CHELABASE_BRANCH_DATA_API_DATABASE_CAP` (default 10)                                                                                                                                               |

## Known limits [#known-limits]

* **Default privileges** cover only objects the owner role (`postgres`) creates. Objects created by any other role (a role you made, or a superuser) get no default grants; grant on them yourself.
* **Settings and schema changes** take up to 60 seconds to take effect (the connection-info cache lifetime). A disable, a `default_schema` change and a narrowed allow-list are pushed to `rest` at once.
* **One database per request:** a request (a batch included) runs in one database. To join data, keep it in one database under several schemas.
* **Revocation lag:** up to 30 seconds per gateway instance.
* **IPv6 rate limiting:** the limiter groups IPv6 clients by `/64` prefix. A load balancer in front collapses all clients into one address unless it is listed in `CHELABASE_GATEWAY_TRUSTED_PROXIES` (see [Hosts](/docs/self-hosting/hosts#behind-a-reverse-proxy)).
* **Limiter size:** it remembers at most 100,000 addresses (idle ones are forgotten after 60 seconds). Past that it evicts entries, and an evicted address starts again with a full allowance.