Date: Thu, 8 Jul 2021 17:17:03 -0500
From: Justin Pryzby <pryzby@telsasoft.com>
To: Nagaraj Raj <nagaraj.sf@yahoo.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Partition column should be part of PK
Message-ID: <20210708221703.GA1301@telsasoft.com>
References: <836265572.4593017.1624590607279.ref@mail.yahoo.com>
 <836265572.4593017.1624590607279@mail.yahoo.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <836265572.4593017.1624590607279@mail.yahoo.com>
User-Agent: Mutt/1.9.4 (2018-02-28)
Archived-At: 
 <https://www.postgresql.org/message-id/20210708221703.GA1301%40telsasoft.com>
Precedence: bulk

If I'm not wrong, this is the same thing you asked 2 week ago.

If so, why not continue the conversation on the same thread, and why not
reference the old thread ?

I went to the effort to find the old conversation.
https://www.postgresql.org/message-id/20210625042228.GJ29179@telsasoft.com

If declaratively partitioned tables and partitioned indexes don't do what you
wanted, then you should consider not using them for this.

On Fri, Jun 25, 2021 at 03:10:07AM +0000, Nagaraj Raj wrote:
> we have some partitioned tables with inherence and planning to migrate them to the declaration.
> Table DDL:
> CREATE TABLE c_account_p
> (
>     billing_account_guid character varying(40)  NOT NULL,
>     ingestion_process_id bigint NOT NULL DEFAULT '-1'::integer,
>     load_dttm timestamp(6) without time zone NOT NULL,
>     ban integer NOT NULL,
>     CONSTRAINT billing_account_pkey PRIMARY KEY (billing_account_guid, ban)
> ) PARTITION by RANGE(load_dttm);
> When I try the create table, it's throwing below error:
> ERROR:  insufficient columns in the PRIMARY KEY constraint definition
> DETAIL:  PRIMARY KEY constraint on table "l_billing_account_p" lacks column "load_dttm" which is part of the partition key.
> SQL state: 0A000
> Is it mandatory/necessary that the partition column should be a primary key? cause if I include load_dttm as PK then it's working fine.db<>fiddle
> If the partition column should be supposed to be a PK, it's challenging to create a partition by range with the date column, cause the load_dttm column chances to have duplicate if data loaded COPY or INSERT.INSERT INTO c_account_p SELECT * from c_account_p_bkp ON CONFLICT (billing_account_guid,ban,load_dttm) DO UPDATE SET 'some stuff..'
> If I receive billing_account_guid, ban combination with different load_dttm then it will end up with duplicate keys.
> Could some please help me to understand this scenario?
> Thanks.