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  1. BUG #18949: 分区表创建主键或者唯一约束需要有分区键

    PG Bug reporting form <noreply@postgresql.org> — 2025-06-07T09:29:06Z

    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。

  2. Re: BUG #18949: 分区表创建主键或者唯一约束需要有分区键

    Dilip Kumar <dilipbalaut@gmail.com> — 2025-06-07T15:55:24Z

    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