Cloudant 中的基准检索

Question

我想从 Cloudant 数据库中检索一组密钥。我尝试了几种方法。但是，custom_result 与其他方法相比执行速度快如闪电。有人可以解释为什么吗？

from cloudant import cloudant
import json
import time
from cloudant.result import Result,ResultByKey


with open('credentials.json') as f:
    cred  = json.load(f)

with cloudant(str(cred['credentials']['username']),str(cred['credentials']['password']),url=str(cred['credentials']['url'])) as client:
    my_database = client['my_database']

    #Using POST
    payload = {"keys": ["012","345"]}
    end_point = '{0}/{1}'.format(client.server_url, 'my_database/_all_docs')
    params = {'include_docs': 'true'}
    start = time.time()
    response = client.r_session.post(end_point, data=json.dumps(payload), params=params)
    end = time.time()
    print end-start


    #using custom_result
    start = time.time()
    result = my_database.custom_result(include_docs=True,keys=["012","345"])
    end = time.time()
    print end-start


    #using all_doc
    start = time.time()
    result = my_database.all_docs(include_docs=True,keys=["012","345"]) 
    end = time.time()
    print end-start


    #using iteration
    keys=["012","345"]
    start = time.time()
    result=[]
    result_collection = Result(my_database.all_docs, include_docs=True)
    for i in range(len(keys)):
        result.append(result_collection[ResultByKey(i)]) 
    end = time.time()
    print end-start

我的输出如下：

0.426064968109
4.10079956055e-05
0.409541845322
0.819295167923

谁能告诉我为什么 custom_result 执行得这么快？

Answer 1

函数 database.custom_result() 仅创建 cloudant.result.Result 实例，Cloudant 不返回任何结果。您可以尝试以这种方式进行测试，结束-开始将是您从 Cloudant 获得响应的整个时间。

start = time.time()
with database.custom_result(include_docs=True) as result:
  data = result[:]
end = time.time()
print end-start

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