# The `queryTimeout` SPARQL query hint
<a name="sparql-query-hints-queryTimeout"></a>

The `queryTimeout` query hint specifies a timeout that is shorter than the `neptune_query_timeout` value set in the DB parameters group.

If the query terminates as a result of this hint, a `TimeLimitExceededException` is thrown, with an `Operation terminated (deadline exceeded)` message. Whether to retry a timed-out query depends on the nature of the failure and your workload. For guidance, see [Exception Handling and Retries](transactions-exceptions.md).

## `queryTimeout` SPARQL hint syntax
<a name="sparql-query-hints-queryTimeout-syntax"></a>

```
PREFIX hint: <http://aws.amazon.com/neptune/vocab/v01/QueryHints#>
SELECT ... WHERE {
    hint:Query hint:queryTimeout 10 .
    # OR
    hint:Query hint:queryTimeout "10" .
    # OR
    hint:Query hint:queryTimeout "10"^^xsd:integer .
 ...
}
```

The time-out value is expressed in milliseconds.

The time-out value must be smaller than the `neptune_query_timeout` value set in the DB parameters group. Otherwise, a `MalformedQueryException` exception is thrown with a `Malformed query: Query hint 'queryTimeout' must be less than neptune_query_timeout DB Parameter Group` message.

The `queryTimeout` query hint should be specified in the `WHERE` clause of the main query, or in the `WHERE` clause of one of the subqueries as shown in the example below.

It must be set only once across all the queries/subqueries and SPARQL Updates sections (such as INSERT and DELETE). Otherwise, a `MalformedQueryException` exception is thrown with a `Malformed query: Query hint 'queryTimeout' must be set only once` message.

**Available Scopes**

The `queryTimeout` hint can be applied both to SPARQL queries and updates.
+ In a SPARQL query, it can appear in the WHERE clause of the main query or a subquery.
+ In a SPARQL update, it can be set in the INSERT, DELETE, or WHERE clause. If there are multiple update clauses, it can only be set in one of them.

For more information about query hint scopes, see [Scope of SPARQL query hints in Neptune](sparql-query-hints.md#sparql-query-hints-scope).

## `queryTimeout` SPARQL hint example
<a name="sparql-query-hints-queryTimeout-example"></a>

Here is an example of using `hint:queryTimeout` in the main `WHERE` clause of an `UPDATE` query:

```
PREFIX hint: <http://aws.amazon.com/neptune/vocab/v01/QueryHints#>
INSERT {
    ?s ?p ?o
} WHERE {
    hint:Query hint:queryTimeout 100 .
    ?s ?p ?o .
}
```

Here, the `hint:queryTimeout` is in the `WHERE` clause of a subquery:

```
PREFIX hint: <http://aws.amazon.com/neptune/vocab/v01/QueryHints#>
SELECT * {
   ?s ?p ?o .
   {
      SELECT ?s WHERE {
         hint:Query hint:queryTimeout 100 .
         ?s ?p1 ?o1 .
      }
   }
}
```