Horton

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

David Rowley <dgrowleyml@gmail.com>

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From: David Rowley <dgrowleyml@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Alvaro Herrera <alvherre@2ndquadrant.com>, Nagaraj Raj <nagaraj.sf@yahoo.com>, Pg Bugs <pgsql-bugs@postgresql.org>
Date: 2020-09-29T23:08:43Z
Lists: pgsql-bugs 
On Wed, 30 Sep 2020 at 11:43, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>
> Alvaro Herrera <alvherre@2ndquadrant.com> writes:
> > On 2020-Sep-29, Tom Lane wrote:
> >> 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.
>
> > Maybe mention PKs in parens:
>
> > "Unique constraints (and[, by extension,] primary key constraints) on
> > partitioned tables must include all the partition key columns. This
> > limitation exists because PostgreSQL can only enforce uniqueness in each
> > partition individually.".
>
> I don't object to clarifying that (and that wording seems fine), but I
> think fixing the error message is more important.  We'd not be having this
> discussion if the OP had found that documentation.

I do agree the error message is the first thing we should be changing.

I'll write a doc patch if you handle the error message.

David

Commits

  1. Reword partitioning error message

  2. Doc: Improve clarity on partitioned table limitations