在Elasticsearch中對大量文檔進行排序

Question

當我想從elasticsearch索引中檢索大量文檔時，我總是使用elasticsearch的掃描和滾動技術（ http://www.elasticsearch.org/guide/en/elasticsearch/guide/current/scan-scroll.html ） 如下：

conn = Elasticsearch( hosts = HOSTS )

the_query = { 'query': { 'match_all': {  } }, 'sort': { 'created_at': { 'order': 'asc' } } } # would like sort the documents according to the 'created_at' date

scanResp = conn.search( index=TARGET_INDEX, doc_type=TARGET_DOC_TYPE, body=the_query, search_type='scan', scroll='10m' )
scrollId = scanResp['_scroll_id']
doc_num = 1

response = conn.scroll( scroll_id = scrollId, scroll='10m' )

while ( len( response['hits']['hits'] ) > 0 ):
    for item in response['hits']['hits']:
        print '\tDocument ' + str(doc_num) + ' of ' + str( response['hits']['total'] )
        doc_num += 1

        # ====================
        #   Process the item
        # ====================
        the_doc = item['_source']


    # end for item
    scrollId = response['_scroll_id']
    if doc_num >= response['hits']['total']:
        break
    response = conn.scroll( scroll_id = scrollId, scroll='10m' )
# end of while

但是，正如elasticsearch文檔中提到的那樣，檢索到的文檔將不會排序，因此結果不是我想要的。

我的問題：如何在Elasticsearch中排序大量文檔？

謝謝 ：）

Answer 1

遍歷排序列表時滾動非常昂貴，但是如果您堅持要從查詢中刪除“ scan” search_type。 滾動時，scan禁用排序。