Date: Tue, 19 Jan 2021 12:42:46 +0100
From: hubert depesz lubaczewski <depesz@depesz.com>
Sender: depesz@depesz.com
To: Anjul Tyagi <anjul@ibosstech-us.com>
Cc: pgsql-admin <pgsql-admin@postgresql.org>
Subject: Re: Table Partitioning
Message-ID: <20210119114246.GA13372@depesz.com>
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References: <em77ea4711-7a8c-4eae-a935-4136d303ea88@iboss01108>
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On Tue, Jan 19, 2021 at 10:21:27AM +0000, Anjul Tyagi wrote:
> Hi All,
> We are using postgres 10.12 and we have one table that size is more then 20Gb. We are planning to do the range partition on that
> table, as we have date filed that can be used. We are able to create partition and it work fine, however one scenario where we are
> getting error. 
> We have created the yearly range for the partition, however we have some scenario where we have to update the date column and
> respective record need to move from other child tables. 
> For ex:
> Table X has 3 partition X2019, X2020, X2021. Column is action_date, that we are using for partitioning. 
> insert one record in X2019 and action date = 2019-11-16
> however now i have to update the date form '2019-11-16' to '2020-02-18', when we try to runt he Update statement, it give me an
> error called "SQL-23514 - new row for relation X2019 violates partition constraint".
> Can you please suggest, how can we handle that scenario? Do I have to write the trigger in Update statement and move the record
> manually or perform the insert and delete operation. 

The simplest solution would be to delete the rows, and immediately
insert into appropriate partition.

for example:

with q as (delete * from x where action = '2019-11-16 returning *)
insert into x select other, columns, '2020-02-18' from q;

depesz