DynamoDB get item count
<p>This code returns the whole set of items, where I need only the count of it. Is it possible to get only the count of the items for this index? </p>

<pre><code>    AWSDynamoDBObjectMapper *objectMapper = [AWSDynamoDBObjectMapper defaultDynamoDBObjectMapper];
AWSDynamoDBQueryExpression *queryExpression = [AWSDynamoDBQueryExpression new];

queryExpression.indexName = @"getVideoViews";
queryExpression.keyConditionExpression = @"#videoId = :val";
queryExpression.expressionAttributeNames = @{
                                             @"#videoId" : @"videoId",
                                             };
queryExpression.expressionAttributeValues = @{
                                              @":val": videoId,
                                              };
__weak typeof(self) weakSelf = self;

[objectMapper query:[ViewedVideos class]
         expression:queryExpression
  completionHandler:^(AWSDynamoDBPaginatedOutput * _Nullable response, NSError * _Nullable error) {
      if (!error) {
          dispatch_async(dispatch_get_main_queue(), ^{
              if ([weakSelf.delegate respondsToSelector:@selector(serverConnectionHandlerReceivedNumberOfVideoViews:)]) {
                  [weakSelf.delegate serverConnectionHandlerReceivedNumberOfVideoViews:3];
              }
          });
      }
  }];
</code></pre>

<p>Like here for example:</p>

<pre><code>aws dynamodb scan --table-name &lt;TABLE_NAME&gt; --select "COUNT"
</code></pre>