LIST-HASH - PolarDB - Alibaba Cloud Documentation Center

This topic describes how to create a list-hash partitioned table.

Syntax

The following statement is used to create one or more list-hash partitioned tables. Partitions are of the LIST [COLUMNS] type. Subpartitions are of the HASH or KEY type.

CREATE TABLE [ schema. ]table_name
 table_definition
   PARTITION BY LIST {(expr)  COLUMNS(column_list)}
   SUBPARTITION BY {[LINEAR] HASH(expr) [SUBPARTITIONS number]
    [LINEAR] KEY [ALGORITHM={1  2}] (column_list)}
   (partition_definition [, partition_definition] ...);

partition_definition is:

 PARTITION partition_name
        VALUES IN ( value_list)
        (subpartition_definition [, subpartition_definition] ...)

partition_definition is:

SUBPARTITION subpartition_name

Parameters

Parameter	Description
expr	The expression of the partition. It must be of the INT type. The string type is not supported.
number	The number of subpartitions.
column_list	The list of partition key columns. Expressions are not supported.
value_list	The list of the boundary values of the partitions.
partition_name	The name of the partition. The name must be unique within the table.
subpartition_name	The name of the subpartition. The name must be unique within the table.

Examples

Create a list-hash partitioned table:

CREATE TABLE sales_list_hash
(
  dept_no     INT,
  part_no     INT,
  country     varchar(20),
  date        DATE,
  amount      INT
)
PARTITION BY LIST(amount)
SUBPARTITION BY HASH(dept_no) SUBPARTITIONS 2
(
  PARTITION p0 VALUES in (1, 2),
  PARTITION p1 VALUES in (3, 4),
  PARTITION p2 VALUES in (5, 6)
);

Create a list columns-hash partitioned table:

CREATE TABLE sales_list_columns_hash
(
  dept_no     INT,
  part_no     INT,
  country     varchar(20),
  date        DATE,
  amount      INT
)
PARTITION BY LIST COLUMNS(country)
SUBPARTITION BY HASH(dept_no) SUBPARTITION 2
(
  PARTITION europe VALUES in ('FRANCE', 'ITALY'),
  PARTITION asia VALUES in ('INDIA', 'PAKISTAN'),
  PARTITION americas VALUES in ('US', 'CANADA')
);