mysql 表分區

 

修改表的主鍵
ALTER TABLE tb_channel_pv DROP PRIMARY KEY,ADD PRIMARY KEY (`id`,`channel`);

 

測試添加分區和刪除分區

 

添加刪除range分區

#(1)創建一個分區：
CREATE TABLE titles (
    emp_no      INT NOT NULL,
    title       VARCHAR(50)     NOT NULL,
    from_date   DATE            NOT NULL,
    to_date     DATE,
    KEY         (emp_no),
    PRIMARY KEY (emp_no,title, from_date)
) partition by range columns(from_date)
(partition p01 values less than ('1985-12-31'),
partition p02 values less than ('1990-12-31'),
partition p03 values less than ('1995-12-31'),
partition p04 values less than ('2000-12-31'),
partition p05 values less than ('2005-12-31'),
partition p06 values less than ('2010-12-31'),
partition p07 values less than ('2015-12-31'),
partition p08 values less than ('2020-12-31'),
partition p09 values less than ('2025-12-31'),
partition p10 values less than ('2030-12-31')
);
 

#(2)添加分區：
#備注：不能超過p04的范圍，嚴格遞增每個分區，即最小不能小於前一個#分區
#下面新曾了兩個分區n01和n02
 alter table titles
 reorganize partition p04 into(
 partition n01 values less than('1997-12-31'),
 partition n02 values less than('1998-12-31'),
 partition p04 values less than('2000-12-31')
 );

#(3)刪除分區：
#刪除分區即刪除數據。
alter table titles drop partition p01; 

 

 

添加刪除list分區

#(1)創建list分區
CREATE TABLE titles (
    emp_no      INT NOT NULL,
    title       VARCHAR(50)     NOT NULL,
    from_date   DATE            NOT NULL,
    to_date     DATE,
    KEY         (emp_no),
    PRIMARY KEY (emp_no,title, from_date)
) partition by list columns(title)
(
partition p0 values in ('Assistant Engineer'),
partition p1 values in ('Engineer'),
partition p2 values in ('Manager'),
partition p3 values in ('Senior Engineer'),
partition p4 values in ('Senior Staff'),
partition p5 values in ('Staff'),
partition p6 values in ('Technique Leader')
);
 

#(2)添加分區
alter table titles add partition(partition p7 values in('CEO'));
 

#(3)刪除分區：
alter table titles drop partition p0;

 

 

 

添加刪除hash分區

#(1)創建hash分區
CREATE TABLE titles (
    emp_no      INT NOT NULL,
    title       VARCHAR(50)     NOT NULL,
    from_date   DATE            NOT NULL,
    to_date     DATE,
    KEY         (emp_no),
    PRIMARY KEY (emp_no,title, from_date)
) partition by hash(emp_no)
partitions 4;
 

#(2)刪除hash分區
4個分區減少到兩個，4-2=2
alter table titles coalesce partition 2; 

#(3)添加hash分區
增加到5個，2+3=5
alter table titles add partition partitions 3;
 

 

 

添加刪除key分區

#(1)創建key分區
CREATE TABLE titles (
    emp_no      INT NOT NULL,
    title       VARCHAR(50)     NOT NULL,
    from_date   DATE            NOT NULL,
    to_date     DATE,
    KEY         (emp_no),
    PRIMARY KEY (emp_no,title, from_date)
) partition by key(emp_no)
partitions 4;
 

#(2)刪除分區，同hash
alter table titles coalesce partition 2;


#(3)添加分區，同hash
alter table titles add partition partitions 3;