python+mysql

抛出问题:处理互联网大量数据,用SQL数据库还是noSql数据库比较好?

今天实习上班,看到前天下班前一小时跑的

每插入一条从一个39W的IP数据库查询属于哪个地区,再插入。总数据94W。太慢。

性能分析,找出瓶颈:

test 1: python+mysql  (单条插入,不是块插入) insert 21039 条数据,耗时0:04:40.790000

                                     join query   与一个表长39W的表join。耗时15min56.61sec

test 2:   python+mysql   块插入 

                                    每次够50条就插入。

             sample:

             

                        data = [
                  ('Jane','555-001'),
                  ('Joe', '555-001'),
                  ('John', '555-003')
                  ]
              stmt = "INSERT INTO employees (name, phone) VALUES (%s,%s)" 注意:%s 不用写成“%s”,没有双引号,和execute()中不一致。
              cursor.executemany(stmt, data)

sample code:

#encoding:utf-8
'''
Created on 2013-1-27
@author: JinHanJiang
'''


'''
create table
CREATE TABLE `Passwords` (
`id` bigint(20) unsigned NOT NULL AUTO_INCREMENT COMMENT 'id主键',
`pass` varchar(64) NOT NULL COMMENT '密码',
`md5` varchar(32) DEFAULT NULL COMMENT '32位md5值',
PRIMARY KEY (`id`),
UNIQUE KEY `pass` (`pass`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8 COMMENT='密码'
'''

import os
import re
import time
from datetime import datetime
import hashlib
import mysql.connector
import random

root_path = os.path.abspath('./') + os.sep 
f = open(root_path + 'file/f1.txt', 'r')
fields = ['pass', 'md5']


def writeDB(params):
conn = cur = None
try:
fields = '(`' + '`, `'.join(params['fields']) + '`)'
stmt = "INSERT IGNORE INTO Passwords"+fields+" VALUES (%s,%s)"

conn = mysql.connector.connect(host='127.0.0.1', database='password', user='root', password='admin')
cur = conn.cursor()
cur.executemany(stmt, params['datas'])
except mysql.connector.Error as e:
print e
finally:
if cur:
cur.close()
if conn:
conn.commit() #如果数据库表类型是Innodb记的带个参数
conn.close()

pos = 0
step = buff = 1024 * 1024
last = ''

dstart = datetime.now()
print "Program Start At: " + dstart.strftime('%Y-%m-%d %H:%M:%S')

while 1:
f.seek(pos)
line = f.read(buff) #从文件中读取一段内容
datas = []

if not line:
if '' is not last:
data = (last, hashlib.md5(last).hexdigest().upper())
datas.append(data)
params = {'fields': fields, 'datas': datas}
writeDB(params)
break; #如果内容为空跳出循环

pos += step #计算取下一段内容长度

lines = re.split("
", line) #以回车(
)分隔内容到数组中

lines[0] = str(last) + str(lines[0]) 
last = lines.pop() #将数组最后一条数据剔除,并存到last变量中,到下次循环再处理

for lin in lines:
lin = lin.rstrip() #去除内容末尾的回车字符
if not lin:
continue

data = (lin, hashlib.md5(lin).hexdigest().upper())
datas.append(data) #封装内容

if len(datas) > 0:
params = {'fields': fields, 'datas': datas}
writeDB(params)

time.sleep(random.random()) #让Cpu随机休息0 <= n < 1.0 s

f.close()

dend = datetime.now()
print "Program End At:%s Time span %s"%(dend.strftime('%Y-%m-%d %H:%M:%S'), dend - dstart);

 

 TEST 3 . 块插入,每条都和IP_data 交互查询(对ip_data表的IPSTART 和IPEND两列建立INDEX)。21000条数据JOIN 39W,耗时21min

 TEST 4 . 块插入,每条都和IP_data 交互查询(对ip_data表的IPSTART 建立INDEX),不用between .用IP>IPSTART ORDER BY IPSTART DESC LIMIT 1。21000条数据JOIN 39W,耗时0:00:21.294000

 

原文地址:https://www.cnblogs.com/karcylee/p/3436912.html