Efficient way to retrieve all _ids in ElasticSearch

Question

What is the fastest way to get all _ids of a certain index from ElasticSearch? Is it possible by using a simple query? One of my index has around 20,000 documents.

Answer 1

This is working!

def select_ids(self, **kwargs):
    """

    :param kwargs:params from modules
    :return: array of incidents
    """
    index = kwargs.get('index')
    if not index:
        return None

    # print("Params", kwargs)
    query = self._build_query(**kwargs)
    # print("Query", query)

    # get results
    results = self._db_client.search(body=query, index=index, stored_fields=[], filter_path="hits.hits._id")
    print(results)
    ids = [_['_id'] for _ in results['hits']['hits']]
    return ids