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help / color / mirror / Atom feedFrom: Raj <rajeshkumar.dba09@gmail.com>
To: Ron Johnson <ronljohnsonjr@gmail.com>
Cc: Pgsql-admin <pgsql-admin@lists.postgresql.org>
Subject: Re: Partitioning table - Update on partitioning key
Date: Fri, 22 May 2026 19:53:51 +0530
Message-ID: <CAJk5AtZm2yyS2E-1=ZYNFZhHRMgJyphG7o-841CBU06RvyfKLQ@mail.gmail.com> (raw)
In-Reply-To: <CANzqJaDCAodT3Fkm3BX=7=KHBxcLuFdKpJeRJpFz3RoKsD541w@mail.gmail.com>
References: <CAJk5AtZH+P1m39F4R2XLtzqgne7Za4qmMTgtBDbU8snXQBrZXQ@mail.gmail.com>
<dd7389df31fe3ac9c1eac94d5ddcb2d51f453f90.camel@cybertec.at>
<CAJk5AtYo4hUFwpKwZGpSzPG3ruTgRPLaKXyVOYn=JGoN29u+Qw@mail.gmail.com>
<CANzqJaDCAodT3Fkm3BX=7=KHBxcLuFdKpJeRJpFz3RoKsD541w@mail.gmail.com>
The error occurs, due to updating the partition key column.
We recently migrated from oracle to postgres.
According to my research, columns that are updated frequently are not best
candidtae for partition key.
With isolation method read committed, if there are concurrent updates on
the same row in different sessions for example( may be updated on different
columns out of which one update is on partition key), updates on the
partition key, may cause the row placed to New partition.
Now, because of MVCC the second update may be looking for row to update in
the old partition itself and that's when we get error.
..
On Thu, 21 May 2026, 23:20 Ron Johnson, <ronljohnsonjr@gmail.com> wrote:
> We'll need to see a "reproducer" (aka short bit of code that reproduces
> your problem), with the output pasted here.
>
> On Thu, May 21, 2026 at 12:12 PM Raj <rajeshkumar.dba09@gmail.com> wrote:
>
>> No, updating the partition key (say colum created_at)....when u update
>> the date , say change march to April, this record is in new partition and
>> we get this error
>>
>> On Thu, 21 May 2026, 17:12 Laurenz Albe, <laurenz.albe@cybertec.at>
>> wrote:
>>
>>> On Thu, 2026-05-21 at 16:45 +0530, Raj wrote:
>>> > Update happing on partition key.
>>> >
>>> > And we get error 'Tuple to be locked was already moved to another
>>> partition due to concurrent update error..
>>> >
>>> > What's the best solution to handle it?
>>>
>>> Could you give us more context, like the exact statement and a
>>> description
>>> of the data it is operating on?
>>>
>>> If I had to guess, I would suspect that your UPDATE statement tries to
>>> modify
>>> the same row more than once.
>>>
>>> Yours,
>>> Laurenz Albe
>>>
>>
>
> --
> Death to <Redacted>, and butter sauce.
> Don't boil me, I'm still alive.
> <Redacted> lobster!
>
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To: pgsql-admin@postgresql.org
Cc: rajeshkumar.dba09@gmail.com, ronljohnsonjr@gmail.com, pgsql-admin@lists.postgresql.org
Subject: Re: Partitioning table - Update on partitioning key
In-Reply-To: <CAJk5AtZm2yyS2E-1=ZYNFZhHRMgJyphG7o-841CBU06RvyfKLQ@mail.gmail.com>
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