Re: ERROR: insufficient columns in the PRIMARY KEY constraint definition

David Rowley <dgrowleyml@gmail.com> writes:
> On Wed, 30 Sep 2020 at 10:36, Nagaraj Raj <nagaraj.sf@yahoo.com> wrote:
>> Is it mandatory/necessary that the `partition column` should be a primary key? cause if I  include `load_dttm` as `PK` then its working fine.

> Yes, this is required.

Indeed.  However, this complaint shows that the error message is not clear
enough.  I propose changing it to

ERROR: unique constraint on partitioned table must be a superset of the partitioning columns

or perhaps

ERROR: unique constraint on partitioned table must include all partitioning columns

The DETAIL seems fine as-is:

DETAIL:  PRIMARY KEY constraint on table "l_billing_account_p" lacks column "load_dttm" which is part of the partition key.

> There's mention in [1] section 5.10.2.3. "Unique constraints on
> partitioned tables must include all the partition key columns. This
> limitation exists because PostgreSQL can only enforce uniqueness in
> each partition individually.". That text likely should also mention
> PRIMARY KEY constraints. That probably should be changed

Meh.  If you've read that bit you probably already understand that
pkeys are unique constraints.  I think the problem is with the error
text not the docs.

			regards, tom lane