MySQL数据库表的合并及分区
1，合并表：把多个结果相同的的表合并为一个容器。
容器的类型：Myisam，存储引擎：merge
存在的问题：有重复的行
<pre class="hljs sql" style="padding: 0.5em; font-family: Menlo, Monaco, Consolas, "Courier New", monospace; color: rgb(68, 68, 68); border-radius: 4px; display: block; margin: 0px 0px 0.75em; font-size: 14px; line-height: 1.5em; word-break: break-all; overflow-wrap: break-word; white-space: pre; background-color: rgb(246, 246, 246); border: none; overflow-x: auto;">create table packtable( id .... )engine=merge unique=(table1,table2);
2，表的分区：
更多技术知识请关注我的V-X-公-众hao：编程经验共享
2.1，水平分区：根据某个字段进行分区（RANGE分区）
<pre class="prettyprint hljs sql" style="padding: 0.5em; font-family: Menlo, Monaco, Consolas, "Courier New", monospace; color: rgb(68, 68, 68); border-radius: 4px; display: block; margin: 0px 0px 1.5em; font-size: 14px; line-height: 1.5em; word-break: break-all; overflow-wrap: break-word; white-space: pre; background-color: rgb(246, 246, 246); border: none; overflow-x: auto;">create table test1( id int(10) primary key auto_increment, score int(3) )engine=innodb default charset=utf8 partition by range(score)( //根据score字段分区，score小于60的在p1分区 partition p1 values less than(60), //根据score字段分区，score小于70的在p2 分区 partition p2 values less than(70), //根据score字段分区，score大于70的在p3 分区 partition p3 values lessthan maxvalue );
2.2 list分区：第一选择基于某 列的值是否属于某个 集合
<pre class="prettyprint hljs sql" style="padding: 0.5em; font-family: Menlo, Monaco, Consolas, "Courier New", monospace; color: rgb(68, 68, 68); border-radius: 4px; display: block; margin: 0px 0px 1.5em; font-size: 14px; line-height: 1.5em; word-break: break-all; overflow-wrap: break-word; white-space: pre; background-color: rgb(246, 246, 246); border: none; overflow-x: auto;">create table test1( id int(10) primary key auto_increment, branch_id int(3) )engine=innodb default charset=utf8 partition by list(branch_id )( //根据branch_id 字段分区，branch_id 在1，2，3之中的为p1分区 partition p1 values less in(1,2,3), //根据branch_id 字段分区，branch_id 在7，8，9 之中的为p2分区 partition p2 values less in(7,8,9) );
2.3 hash分区：支持数值类型
<pre class="prettyprint hljs sql" style="padding: 0.5em; font-family: Menlo, Monaco, Consolas, "Courier New", monospace; color: rgb(68, 68, 68); border-radius: 4px; display: block; margin: 0px 0px 1.5em; font-size: 14px; line-height: 1.5em; word-break: break-all; overflow-wrap: break-word; white-space: pre; background-color: rgb(246, 246, 246); border: none; overflow-x: auto;">-- -- 根据birthda字段获取月份，再根据月份进行分区储存，一共分12个区； -- create table test1( id int(10) primary key auto_increment, birthday date )engine=innodb default charset=utf8 partition by hash(month(birthday)) partitions 12;
2.4 线性分区（linear hash)：大数据是增加，合并，拆分速度更快
<pre class="prettyprint hljs sql" style="padding: 0.5em; font-family: Menlo, Monaco, Consolas, "Courier New", monospace; color: rgb(68, 68, 68); border-radius: 4px; display: block; margin: 0px 0px 1.5em; font-size: 14px; line-height: 1.5em; word-break: break-all; overflow-wrap: break-word; white-space: pre; background-color: rgb(246, 246, 246); border: none; overflow-x: auto;">-- -- 根据branch_id字段进行分区储存，一共分5个区； -- create table test1( id int(10) primary key auto_increment, branch_id int(3) )engine=innodb default charset=utf8 partition by linear hash (branch_id ) partitions 5;
2.5 key分区：可以计算一列或者多列进行分区
<pre class="prettyprint hljs sql" style="padding: 0.5em; font-family: Menlo, Monaco, Consolas, "Courier New", monospace; color: rgb(68, 68, 68); border-radius: 4px; display: block; margin: 0px 0px 1.5em; font-size: 14px; line-height: 1.5em; word-break: break-all; overflow-wrap: break-word; white-space: pre; background-color: rgb(246, 246, 246); border: none; overflow-x: auto;">-- -- 根据branch_id字段进行分区储存，一共分5个区； -- create table test1( id int(10) primary key auto_increment, branch_id int(3) )engine=innodb default charset=utf8 partition by key (branch_id ) partitions 5;#MySQL##java#
