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@postgresql.org> wrote:

The following bug has been logged on the website:

Bug reference: 18949
Logged by: 余 大海
Email address: 1157357742@qq.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