Subject: Re: Partitioning on the date part of a timestamp & PK issues
To: pgsql-admin@lists.postgresql.org
References: <202107160253.va6esfntkuxr@alvherre.pgsql>
From: Ron <ronljohnsonjr@gmail.com>
Message-ID: <d5cd0231-32ab-540e-f354-45dd23ed4130@gmail.com>
Date: Thu, 15 Jul 2021 22:45:12 -0500
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On 7/15/21 9:53 PM, Alvaro Herrera wrote:
> On 2021-Jul-15, Ron wrote:
>
>> CREATE TABLE t (
>>      guid uuid not null,
>>      seq smallint not null,
>>      tid smallint not null,
>>      ts timestamp without time zone not null,
>>      x real,
>>      y real,
>>      z real,
>>      primary key (guid, tid, seq, ts)
>> )   partition by range (ts);
> This definition will let you have multiple rows for the same
> (guid,tid,seq) combination, as long as they have different ts values.
> That is at odds with the original formulation, in which there could be a
> single row with any given combination of those three columns.

That's the cost of partitioning by something other than uid, tid or seq.

-- 
Angular momentum makes the world go 'round.