Python 验证MongoDB中$set、$inc、$push几种修改器操作的速度

水电工888

　　Python 验证MongoDB中$set、$inc、$push几种修改器操作的速度
　　

　　在MongoDB中，$set、$inc、$push都能够对数据库进行操作，那么到底哪种修改器操作速度更快呢？我们今天来验证一下。
　　先描述一下本人的实验环境：
　　 Win8操作系统64位，内装虚拟机32位系统，CentOS5.5
　　

　　实验第一步，安装并启动MongoDB数据库服务器：
　　在CentOS下如何安装MongoDB数据库如果有疑问的请猛击如下链接http://blog.csdn.net/yima1006/article/details/9840239

    [iyunv@h3 home]# mongod -f /etc/mongod.conf
Thu Jul 25 00:19:15.950
Thu Jul 25 00:19:15.950 warning: 32-bit servers don't have journaling enabled by default. Please use --journal if you want durability.
Thu Jul 25 00:19:15.950
about to fork child process, waiting until server is ready for connections.
forked process: 14519
all output going to: /var/log/mongo/mongod.log
child process started successfully, parent exiting
[iyunv@h3 home]#


实验第二步，编辑测试文件，这里我们保存为test.py，文件内容如下：
    #!usr/bin/python
#coding=utf-8
from pymongo import Connection
import time
db = Connection().performance_test
db.drop_collection("updates")
collection = db.updates
collection.insert({"x": 1})
collection.find_one()
# in inc test
start_inc = time.time()
for i in range(100000):
collection.update({}, {"$inc" : {"x" : 1}})
collection.find_one()
print '$inc:', time.time() - start_inc
# in set  test
start_set = time.time()
for i in range(100000):
collection.update({}, {"$set" : {"x" : 1}})
collection.find_one()
print '$set:', time.time() - start_set
# in push test
start_push = time.time()
for i in range(100000):
collection.update({}, {"$push" : {"x" : 1}})
collection.find_one()
print '$push:', time.time() - start_push

　　实验第三步，我们运行测试test.py，这里我们运行5次

    [iyunv@h3 home]# python test.py
$inc: 6.83732295036
$set: 6.61989808083
$push: 10.5028648376
[iyunv@h3 home]# python test.py
$inc: 6.56225991249
$set: 6.12179207802
$push: 10.264081955
[iyunv@h3 home]# python test.py
$inc: 6.18113183975
$set: 6.4468960762
$push: 10.077311039
[iyunv@h3 home]# python test.py
$inc: 6.19089698792
$set: 6.61814904213
$push: 9.5483288765
[iyunv@h3 home]# python test.py
$inc: 6.93615078926
$set: 6.58752202988
$push: 9.91513586044
[iyunv@h3 home]#

　　结论：在MongoDB中，$inc、$set 修改器的操作速度相差不大，但明显快于$push修改器。