When working with a large table, table partitioning divides the table into several subsets of data based on the given criteria and helps the database system to process one partition instead of scanning the whole table. That helps with the performance matter. In MySQL, there are four partitioning...
as the first builds of the MySQL 5.1 hits the street. The MySQL 5.1 is already now source downloadable, most of the commands above already exists there, however not in its optimised version yet. This code is just entering the review stage. ...
bit_expr 语义组用于解析 “位表达式”,即在简单表达式(simple_expr)的基础上使用各种数值类二元运算符进行计算的表达式,详见 MySQL 源码|69 - 语法解析(V2):位表达式(bit_expr)。 语义组:part_values_in part_values_in 语义组用于解析 PARTITION BY 子句中被括号框柱的、分区内可选值的列表。 返回值类型:PT...
Hash分区:对用户定义的表达式所返回的值来进行分区。可以写partitions (分区数目),或直接使用分区语句,比如partition p0 values in…..。 Key分区:与hash分区类似,只不过分区支持一列或多列,并且MySQL服务器自身提供hash函数。 具体描述: 分区语法: create table t(id int,name varchar(20)) engine=myisam partiti...
Note In MySQL 5.7, all partitions of a partitioned table must have the same number of subpartitions, and it is not possible to change the subpartitioning once the table has been created. To change a table's partitioning scheme, it is necessary only to use theALTER TABLEstatement with apar...
Statements using partition selection can be employed with tables using any of the partitioning types supported in MySQL 5.7. When a table is created using [LINEAR] HASH or [LINEAR] KEY partitioning and the names of the partitions are not specified, MySQL automatically names the partitions p0, p1...
Hash分区:对用户定义的表达式所返回的值来进行分区。可以写partitions (分区数目),或直接使用分区语句,比如partition p0 values in…..。 Key分区:与hash分区类似,只不过分区支持一列或多列,并且MySQL服务器自身提供hash函数。 具体描述: 分区语法: create table t(id int,name varchar(20)) engine=myisam partiti...
mysql> alter table example_db.expamle_list_tbl add partition p_uk VALUES IN ("L"); Query OK, 0 rows affected (0.01 sec) 查询分区。 mysql> show partitions from example_db.expamle_list_tbl; +---+---+---+---+---+---+---...
Description:ALTER TABLE OPTIMIZE PARTITION appears to not work on innodb tables. Multiple-partition tables are also affected; other partition types are also affected; tables with actual rows are also affected; myisam works as expected;How to repeat:mysql> CREATE TABLE part1_range (f1 integer) T...
as the first builds of the MySQL 5.1 hits the street. The MySQL 5.1 is already now source downloadable, most of the commands above already exists there, however not in its optimised version yet. This code is just entering the review stage. ...