n, err := io.Copy(clientConn, r)
	if err != nil {
		t.Fatal(err)
	}

	if n != int64(len(data)) {
		t.Errorf("io.Copy returned %d, want %d", n, len(data))
	}

	clientConn.Close()
	tot := <-ch

	if tot != len(data) {
		t.Errorf("server read %d, want %d", tot, len(data))
	}

When deploying applications you will probably want to have some **replication of processes** to take advantage of **multiple cores** and to be able to handle more requests.

# SQL (Relational) Databases { #sql-relational-databases }

**FastAPI** doesn't require you to use a SQL (relational) database. But you can use **any database** that you want.

Here we'll see an example using <a href="https://sqlmodel.tiangolo.com/" class="external-link" target="_blank">SQLModel</a>.

For example, let's say that you want to use <a href="https://github.com/ijl/orjson" class="external-link" target="_blank">`orjson`</a>, but with some custom settings not used in the included `ORJSONResponse` class.

Let's say you want it to return indented and formatted JSON, so you want to use the orjson option `orjson.OPT_INDENT_2`.

<img src="/img/tutorial/query-param-models/image01.png">
</div>

## Forbid Extra Query Parameters { #forbid-extra-query-parameters }

In some special use cases (probably not very common), you might want to **restrict** the query parameters that you want to receive.

You can use Pydantic's model configuration to `forbid` any `extra` fields:

{* ../../docs_src/query_param_models/tutorial002_an_py310.py hl[10] *}

  protected CountDownLatch latch;
  protected ListenableFuture<Boolean> future;

  @Override
  protected void setUp() throws Exception {

    // Create a latch and a future that waits on the latch.
    latch = new CountDownLatch(1);
    future = createListenableFuture(Boolean.TRUE, null, latch);
  }

  @Override
  protected void tearDown() throws Exception {

              <testTimeOut>86400 <!-- seconds --></testTimeOut>
              <testMethodTimeout>1440 <!-- minutes --></testMethodTimeout>
              <!-- Presumably we want watchFileChanges=false here, since we want it for compile: -->
              <extraJvmArgs>-Dgwt.watchFileChanges=false</extraJvmArgs>
            </configuration>
          </execution>
        </executions>
      </plugin>

		err := tryParse(t, func() {
			parser.Parse()
		})

		switch {
		case err == nil:
			t.Errorf("#%d: %q: want error %q; have none", i, test.input, test.error)
		case !strings.Contains(err.Error(), test.error):
			t.Errorf("#%d: %q: want error %q; have %q", i, test.input, test.error, err)
		}
	}

  override fun getUseClientMode(): Boolean = delegate!!.useClientMode

  override fun setNeedClientAuth(need: Boolean) {
    delegate!!.needClientAuth = need
  }

  override fun setWantClientAuth(want: Boolean) {
    delegate!!.wantClientAuth = want
  }

  override fun getNeedClientAuth(): Boolean = delegate!!.needClientAuth

  override fun getWantClientAuth(): Boolean = delegate!!.wantClientAuth

```Python hl_lines="3" title="app/internal/admin.py"
{!../../docs_src/bigger_applications/app/internal/admin.py!}
```

But we still want to set a custom `prefix` when including the `APIRouter` so that all its *path operations* start with `/admin`, we want to secure it with the `dependencies` we already have for this project, and we want to include `tags` and `responses`.