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亲身体验MySQL的索引对搜索性能的提升

2014年05月11日23:17 阅读: 25844 次

标签: 亲身体验MySQL的索引对搜索性能的提升

1,创建一个user表,包含两列name,phone

2,用python(你喜欢的任何语言)插入100W条记录(lz的笔记本比较老,大概用了1分钟吧):

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#!/usr/bin/env python
# -*- coding:utf-8 -*-
 
import MySQLdb
 
conn =  MySQLdb.connect(host='localhost',user='root',db='millionMessage')
cur = conn.cursor()
 
for i in range(1,1000000):
    uname = "user" + str(i)
    uphone = "188000" + str(i)
    sql = "insert into user(name,phone) values('%s','%s')" % (uname,uphone)
    cur.execute(sql)
 
conn.commit()
cur.close()
conn.close()
3,在没建立索引的情况下搜索:

mysql> select * from user where name='user55555';
+-------+-----------+-------------+
| uid | name | phone |
+-------+-----------+-------------+
| 55567 | user55555 | 18800055555 |
+-------+-----------+-------------+
1 row in set (0.53 sec)

mysql> select phone from user where name='user55555';
+-------------+
| phone |
+-------------+
| 18800055555 |
+-------------+
1 row in set (0.46 sec)

4,对name属性建立索引:

mysql> alter table user add index index_username(name);
Query OK, 0 rows affected (22.27 sec)
Records: 0 Duplicates: 0 Warnings: 0

5, 查询:

mysql> select * from user where name='user55555';
+-------+-----------+-------------+
| uid | name | phone |
+-------+-----------+-------------+
| 55567 | user55555 | 18800055555 |
+-------+-----------+-------------+
1 row in set (0.00 sec)

mysql> select * from user where name='user999999';
+---------+------------+--------------+
| uid | name | phone |
+---------+------------+--------------+
| 1000011 | user999999 | 188000999999 |
+---------+------------+--------------+
1 row in set (0.00 sec)

结果秒出。可见在海量数据的数据库上,索引对搜索性能的提升是非常大的。

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