Re: BUG #18949: 分区表创建主键或者唯一约束需要有分区键

On Sat, Jun 7, 2025 at 9:12 PM PG Bug reporting form
<noreply(at)postgresql(dot)org> wrote:
>
> The following bug has been logged on the website:
>
> Bug reference: 18949
> Logged by: 余 大海
> Email address: 1157357742(at)qq(dot)com
> PostgreSQL version: 16.2
> Operating system: centos7.9
> Description:
>
> postgres=# CREATE TABLE hash_sales (
> postgres(# id INT,
> postgres(# sale_date DATE,
> postgres(# amount NUMERIC,
> postgres(# PRIMARY KEY (id) -- 主键必须包含分区键
> postgres(# ) PARTITION BY hash(sale_date );
> ERROR: unique constraint on partitioned table must include all partitioning
> columns
> DETAIL: PRIMARY KEY constraint on table "hash_sales" lacks column
> "sale_date" which is part of the partition key.
> 在oracle中，以上SQL语句可以创建成功，并能保证ID的全局唯一性，但是在PG15\16\17中，分区表创建主键或者唯一约束都需要有分区键，这样会导致ID字段的无法保证全局唯一性。PG18released
> 中也并没有对此的改进。

PostgreSQL's partitioned tables have a known limitation: unique
constraints (including primary keys) must include all columns of the
partitioning key. This isn't a bug, but a design constraint.
For example, if you partition hash_sales by sale_date, your primary
key must include sale_date. as shown below

CREATE TABLE hash_sales (
id INT,
sale_date DATE,
amount NUMERIC,
PRIMARY KEY (sale_date, id)
) PARTITION BY hash(sale_date);

--
Regards,
Dilip Kumar
Google