For example, when using GraphQL you normally perform all the actions using only `POST` operations.

///

### Step 4: define the **path operation function** { #step-4-define-the-path-operation-function }

This is our "**path operation function**":

* **path**: is `/`.
* **operation**: is `get`.
* **function**: is the function below the "decorator" (below `@app.get("/")`).

which are made up of goroutine executions,
which in turn are made up of memory operations.
</p>

<p>
A <i>memory operation</i> is modeled by four details:
</p>
<ul>
	<li>its kind, indicating whether it is an ordinary data read, an ordinary data write,
    or a <i>synchronizing operation</i> such as an atomic data access,
	a mutex operation, or a channel operation,</li>
	<li>its location in the program,</li>

```

...eso es porque el generador del cliente usa el **operation ID** interno de OpenAPI para cada *path operation*.

OpenAPI requiere que cada operation ID sea único a través de todas las *path operations*, por lo que FastAPI usa el **nombre de la función**, el **path**, y el **método/operación HTTP** para generar ese operation ID, porque de esa manera puede asegurarse de que los operation IDs sean únicos.

`mc admin bucket remote add` does not apply to `DELETE` operations. The version being deleted on the source cluster needs to maintain state and ensure that the operation is mirrored to the target cluster prior to completing on the source object version. Since this needs to account for the target cluster availability and the need to serialize concurrent DELETE operations on different versions of the same object during multi DELETE operations, the current implementation queues the `DELETE` operations...

* `PUT`: um Daten zu aktualisieren (update).
* `DELETE`: um Daten zu löschen (delete).

In OpenAPI wird folglich jede dieser HTTP-Methoden als „Operation“ bezeichnet.

Wir werden sie auch „**Operationen**“ nennen.

#### Definieren eines *Pfadoperation-Dekorators* { #define-a-path-operation-decorator }

{* ../../docs_src/first_steps/tutorial001_py39.py hl[6] *}

```

...that's because the client generator uses the OpenAPI internal **operation ID** for each *path operation*.

OpenAPI requires that each operation ID is unique across all the *path operations*, so FastAPI uses the **function name**, the **path**, and the **HTTP method/operation** to generate that operation ID, because that way it can make sure that the operation IDs are unique.

But I'll show you how to improve that next. 🤓

# Background Tasks { #background-tasks }

You can define background tasks to be run *after* returning a response.

This is useful for operations that need to happen after a request, but that the client doesn't really have to be waiting for the operation to complete before receiving the response.

This includes, for example:

* Email notifications sent after performing an action:

//              below).
//  opers - Array of operations to become the body of the function or null.
//          - If no array is given (`num_opers` = -1), all the
//          operations in `fn_body` will become part of the function
//          except operations referenced in `inputs`. These operations
//          must have a single output (these operations are typically

        stacklevel=2,
    )
    operation_id = f"{name}{path}"
    operation_id = re.sub(r"\W", "_", operation_id)
    operation_id = f"{operation_id}_{method.lower()}"
    return operation_id


def generate_unique_id(route: "APIRoute") -> str:
    operation_id = f"{route.name}{route.path_format}"
    operation_id = re.sub(r"\W", "_", operation_id)
    assert route.methods

Swagger UI will handle it behind the scenes for you, but it needs this "redirect" helper.

///

### Create a *path operation* to test it { #create-a-path-operation-to-test-it }

Now, to be able to test that everything works, create a *path operation*:

{* ../../docs_src/custom_docs_ui/tutorial001_py39.py hl[36:38] *}

### Test it { #test-it }