创建分区表

本文介绍了创建分区表的语法、各种类型分区表的示例等内容。

语法

CREATE TABLE [ schema. ]<table_name>
   <table_definition>
   PARTITION BY LIST(<column>) 
   [SUBPARTITION BY {RANGE|LIST|HASH} (<column>[, <column> ]...)]
   (<list_partition_definition>[, <list_partition_definition>]...)
   [ENABLE ROW MOVEMENT];

Where list_partition_definition is:

      PARTITION [<partition_name>]
        VALUES (<value>[, <value>]...)
        [TABLESPACE <tablespace_name>]
        [(<subpartition>, ...)]

1. Range Partitioning Syntax
CREATE TABLE [ schema. ]<table_name>
   <table_definition>
   PARTITION BY RANGE(<column>[, <column> ]...)
   [SUBPARTITION BY {RANGE|LIST|HASH} (<column>[, <column> ]...)]
   (<range_partition_definition>[, <range_partition_definition>]...)
   [ENABLE ROW MOVEMENT];

Where range_partition_definition is:
      PARTITION [<partition_name>]
        VALUES LESS THAN (<value>[, <value>]...)
        [TABLESPACE <tablespace_name>]
        [(<subpartition>, ...)]
2. Hash Partitioning Syntax
CREATE TABLE [ schema. ]<table_name>
   <table_definition>
   PARTITION BY HASH(<column>[, <column> ]...)
   [SUBPARTITION BY {RANGE|LIST|HASH} (<column>[, <column> ]...)]
   (<hash_partition_definition>[, <hash_partition_definition>]...)
   [ENABLE ROW MOVEMENT];

Where hash_partition_definition is:
      PARTITION [<partition_name>]
        [TABLESPACE <tablespace_name>]
        [(<subpartition>, ...)]

3. Subpartitioning Syntax
{<list_subpartition> | <range_subpartition> | <hash_subpartition>}

where list_subpartition is:

      SUBPARTITION [<subpartition_name>]
        VALUES (<value>[, <value>]...)
        [TABLESPACE <tablespace_name>]

where range_subpartition is:

      SUBPARTITION [<subpartition_name>]
        VALUES LESS THAN (<value>[, <value>]...)
        [TABLESPACE <tablespace_name>]

where hash_subpartition is:

      SUBPARTITION [<subpartition_name>]
        [TABLESPACE <tablespace_name>]

示例

创建范围分区表

CREATE TABLE sales(dept_no number, date date)
PARTITION BY RANGE(date)
(
  PARTITION q1_2012 VALUES LESS THAN('2012-Apr-01'),
  PARTITION q2_2012 VALUES LESS THAN('2012-Jul-01'),
  PARTITION q3_2012 VALUES LESS THAN('2012-Oct-01'),
  PARTITION q4_2012 VALUES LESS THAN('2013-Jan-01')
);

创建列表分区表

CREATE TABLE sales (dept_no number, country varchar2(20))
PARTITION BY LIST(country)
(
  PARTITION europe VALUES('FRANCE', 'ITALY'),
  PARTITION asia VALUES('INDIA', 'PAKISTAN'),
  PARTITION americas VALUES('US', 'CANADA')
);

创建哈希分区表

CREATE TABLE sales (dept_no number, part_no varchar2)
PARTITION BY HASH (part_no)
(
  PARTITION p1,
  PARTITION p2,
  PARTITION p3
);

创建二级分区表

说明

PolarDB PostgreSQL版(兼容Oracle)在创建分区表时需要指定分区,同样在创建分区时也可指定二级分区,Oracle语法中最大的分区级别为二级分区(也称为子分区)。

CREATE TABLE sales
(
  dept_no     number,
  part_no     varchar2,
  country     varchar2(20),
  date        date,
  amount      number
)
PARTITION BY RANGE(date)
  SUBPARTITION BY LIST(country)
  (
    PARTITION q1_2012
      VALUES LESS THAN('2012-Apr-01')
      (
        SUBPARTITION q1_europe VALUES ('FRANCE', 'ITALY'),
        SUBPARTITION q1_asia VALUES ('INDIA', 'PAKISTAN'),
        SUBPARTITION q1_americas VALUES ('US', 'CANADA')
      ),
  PARTITION q2_2012
    VALUES LESS THAN('2012-Jul-01')
      (
        SUBPARTITION q2_europe VALUES ('FRANCE', 'ITALY'),
        SUBPARTITION q2_asia VALUES ('INDIA', 'PAKISTAN'),
        SUBPARTITION q2_americas VALUES ('US', 'CANADA')
      ),
  PARTITION q3_2012
    VALUES LESS THAN('2012-Oct-01')
      (
        SUBPARTITION q3_europe VALUES ('FRANCE', 'ITALY'),
        SUBPARTITION q3_asia VALUES ('INDIA', 'PAKISTAN'),
        SUBPARTITION q3_americas VALUES ('US', 'CANADA')
      ),
  PARTITION q4_2012
    VALUES LESS THAN('2013-Jan-01')
      (
        SUBPARTITION q4_europe VALUES ('FRANCE', 'ITALY'),
        SUBPARTITION q4_asia VALUES ('INDIA', 'PAKISTAN'),
        SUBPARTITION q4_americas VALUES ('US', 'CANADA')
      )
);