使用匹配所有查询从 Elastic 搜索索引中获取有限数据 python

Question

我正在编写一个 python 程序来从弹性搜索索引中获取数据。我想根据我指出的最多 25 个匹配查询获取数据。我想要前 25 个数据。我索引中的数据是 10842。但它从弹性搜索的索引中检索所有数据。我从这里检查了解决方案，但它对我没有帮助。帮我解决一些问题

代码如下：

from elasticsearch import Elasticsearch
import elasticsearch.helpers

count = 0
host = 'localhost'
ind = 'apps'
doc_typ = "change_apps"
limit_count = 25

def elasticsearch_import(host,ind,doc_typ,count,limit_count,port=9200,query={},single_line=False,single_line_label="message"):
    data_count=count+limit_count
    print("Data to be get from Elastic Search: ",data_count)
    es = Elasticsearch()

    results = elasticsearch.helpers.scan(es,
    index=ind,
    doc_type=doc_typ,
    preserve_order=True,
    query={"from":count,"size":data_count,"query": {"bool": {"must": [{"match_all": {}}],"must_not": [],"should": [] }},})
    res=[]
    for i in results:
        res.append(i)
    #print("res",res)
    print("Data got from Elastic Search",len(res))

elasticsearch_import(host,ind,doc_typ,count,limit_count)

我得到的输出：

Data to be get from Elastic Search:  25
Data got from Elastic Search 10842

所需输出：

Data to be get from Elastic Search:  25
Data got from Elastic Search 25

Answer 1

这就是scan方法的作用...它使用scroll method under the hood, if you look into the api documentation，size实际上意味着batch size。

size – size (per shard) of the batch send at each iteration.

如果你只是想得到一个大小的结果，search就足够了，在这种情况下，size是结果大小，默认值是10.

使用匹配所有查询从 Elastic 搜索索引中获取有限数据 python

fetch limited data from Elastic search indices using match all query python

python-3.x

elasticsearch

elasticsearch-plugin

elastic-stack

elasticsearch-5