mysql数据库分区及测试

1、 测试数据库是否支持分区

mysql可以通过下面语句判断是否支持分区：

SHOW VARIABLES LIKE '%partition%';

如果输出：have_partitioning   YES 表示支持分区。

或者通过：SHOW PLUGINS;

显示所有插件，如果有partition ACTIVE STORAGE ENGINE GPL 插件则表明支持分区

2、 创建测试表格

3、 将原表格数据复制到测试的表格

Insert into table_test select * from table

4、 对测试表格进行分区

alter table ta_monitor _history_test partition by RANGE (to_days(monitor_time))

(PARTITION p0 VALUES LESS THAN (to_days('2018-01-01')),

PARTITION p1 VALUES LESS THAN (to_days('2018-03-01')) , PARTITION p2 VALUES LESS THAN (to_days('2018-05-01')) ,

PARTITION p3 VALUES LESS THAN (to_days('2018-06-01')) , PARTITION p4 VALUES LESS THAN (to_days('2018-07-01')) ,

PARTITION p5 VALUES LESS THAN (to_days('2018-08-01')) , PARTITION p6 VALUES LESS THAN (to_days('2018-09-01')) ,

PARTITION p7 VALUES LESS THAN (to_days('2018-10-01')) , PARTITION p8 VALUES LESS THAN (to_days('2018-11-01')) ,

PARTITION p9 VALUES LESS THAN (to_days('2018-12-01')) , PARTITION p10 VALUES LESS THAN (to_days('2019-01-01')),

PARTITION p11 VALUES LESS THAN (to_days('2019-02-01')), PARTITION P12 VALUES LESS THAN (to_days('2019-03-01')),

PARTITION P13 VALUES LESS THAN (to_days('2019-04-01')), PARTITION P14 VALUES LESS THAN (to_days('2019-05-01')),

PARTITION P15 VALUES LESS THAN (to_days('2019-06-01')), PARTITION P16 VALUES LESS THAN (to_days('2019-07-01')),

PARTITION P17 VALUES LESS THAN (to_days('2019-08-01')), PARTITION P18 VALUES LESS THAN (to_days('2019-09-01')),

PARTITION P19 VALUES LESS THAN (to_days('2019-10-01')), PARTITION P20 VALUES LESS THAN (to_days('2019-11-01')),

PARTITION P21 VALUES LESS THAN (to_days('2019-12-01')), PARTITION P22 VALUES LESS THAN (to_days('2020-01-01')),

PARTITION P23 VALUES LESS THAN (to_days('2020-02-01')), PARTITION P24 VALUES LESS THAN (to_days('2020-03-01')),

PARTITION P25 VALUES LESS THAN MAXVALUE );

5、 查看分区

SELECT  *  FROM

INFORMATION_SCHEMA.partitions

WHERE

TABLE_SCHEMA = SCHEMA()

AND TABLE_NAME='ta_monitor _history_test';

6、 测试分区

EXPLAIN SELECT

*

FROM

`ta_monitor _history`

WHERE monitor_time > '2018-07-01 01:00:00'

AND monitor_time< '2018-07-19 00:00:00';

EXPLAIN SELECT

*

FROM

`ta_monitorr_history_test`

WHERE monitor_time > '2018-07-01 01:00:00'

AND monitor_time< '2018-07-19 00:00:00';

Rows显示遍历了多少行。

7、 重新定义range分区表:

Alter table emp partitionbyrange(salary)

(partition p1 values less than (2000),

partition p2 values less than (4000)); ----不会丢失数据

8、删除表的所有分区:

Alter table emp removepartitioning;--不会丢失数据

9、可以查看创建分区表的create语句

show create table 表名