1.分表原因

1.資料過多，訪問緩慢

2.建立索引時重新排序，建立緩慢，並且佔用大量的磁碟空間

2.分表方式

1.根據資料範圍分表
2.根據取模的方式(取餘數)

3.Atlas分表

1.分表思路

1.確定分表的庫，表，欄位
2.確定分表的數量
3.分表的名字，stu_0,stu_1,stu_2
4.配置檔案配置分表的規則
5.測試

2.配置 Atlas

[root@db03 ~]# vim /usr/local/mysql-proxy/conf/test.cnf
#分表設定，此例中school為庫名，stu為表名，id為分表字段，3為子表數量，可設定多項，以逗號分隔，若不分表則不需要設定該項
tables = school.stu.id.3



# 重啟 Atlas
[root@db03 ~]# /usr/local/mysql-proxy/bin/mysql-proxyd test restart
OK: MySQL-Proxy of test is stopped
OK: MySQL-Proxy of test is started
 

3.建立原表

# 連線Atlas負載資料庫
[root@db03 ~]# mysql -umha -pmha -h127.0.0.1 -P 1234

# 建立資料庫
mysql> create database school;
Query OK, 1 row affected (0.00 sec)

# 建立資料表
mysql> use school
Database changed
mysql> create table stu(id int,name varchar(10));
Query OK, 0 rows affected (0.13 sec)

4.建立分表

# 建立分表，表名要保證如下格式，否則報錯
mysql> create table stu_0 like stu;
Query OK, 0 rows affected (0.08 sec)

mysql> create table stu_1 like stu;
Query OK, 0 rows affected (0.03 sec)

mysql> create table stu_2 like stu;
Query OK, 0 rows affected (0.03 sec)
 

5.資料測試

# 插入資料
mysql> insert into stu values(1,'wqh');
Query OK, 1 row affected (0.01 sec)

mysql> insert into stu values(2,'wqh');
Query OK, 1 row affected (0.00 sec)

mysql> insert into stu values(3,'wqh3');
Query OK, 1 row affected (0.01 sec)

mysql> insert into stu values(11,'wqh3');
Query OK, 1 row affected (0.01 sec)

mysql> insert into stu values(12,'wqh3');
Query OK, 1 row affected (0.00 sec)

mysql> insert into stu values(13,'wqh3');
Query OK, 1 row affected (0.02 sec)

# 檢視資料
mysql> select * from stu;
Empty set (0.00 sec)

mysql> select * from stu_0;
+------+------+
| id   | name |
+------+------+
|    3 | wqh3 |
|   12 | wqh3 |
+------+------+
2 rows in set (0.03 sec)

mysql> select * from stu_1;
+------+------+
| id   | name |
+------+------+
|    1 | wqh  |
|   13 | wqh3 |
+------+------+
2 rows in set (0.00 sec)

mysql> select * from stu_2;
+------+------+
| id   | name |
+------+------+
|    2 | wqh  |
|   11 | wqh3 |
+------+------+
2 rows in set (0.00 sec)

# 如果想檢視原表資料，需要加 where條件
mysql> select * from stu where id=1;
+------+------+
| id   | name |
+------+------+
|    1 | wqh  |
+------+------+
1 rows in set (0.00 sec)