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From: Gambhir Singh <[email protected]>
To: Ron Johnson <[email protected]>
Cc: Pgsql-admin <[email protected]>
Subject: Re: Update command causing lock in DB.
Date: Thu, 8 May 2025 15:02:35 +0530
Message-ID: <CAHOGQfXSJEMLXA_jMySNHm0KP06nGkAfuL2nhqDrj1Wde95g5g@mail.gmail.com> (raw)
In-Reply-To: <CANzqJaDP=Eg_9d6aN4C8oy-na-MJhXyP7zAqLJhekBqxs75eUA@mail.gmail.com>
References: <CAHOGQfWk-xb3q0QSXY=xUsMohChEEZwjxoTzrFUK+D_GEcO+uw@mail.gmail.com>
	<CANzqJaDP=Eg_9d6aN4C8oy-na-MJhXyP7zAqLJhekBqxs75eUA@mail.gmail.com>

They are using explicit transaction block and also got he root cause. They
to provide the commit explicitly.

Thanks & Regards
Gambhir Singh



On Wed, 7 May 2025 at 19:01, Ron Johnson <[email protected]> wrote:

> On Wed, May 7, 2025 at 7:16 AM Gambhir Singh <[email protected]>
> wrote:
>
>> Hi,
>>
>> Application team was executing UPDATE statement in DB through Abinitio
>> graph. When they trigger a job, a session is spawned in DB, in parallel
>> another session is also spawned and executed the same UPDATE statement.
>>
>> When I checked the locks in DB, I found that both the sessions are
>> updating the same record. My concern is how UPDATE causes locking in DB.
>>
>> Here is how MVCC works. If one session is updating a record, it should
>> release the lock once it updated the row and other one should be able to
>> acquire the row lock. Maybe I am wrong, please suggest how to handle this
>> situation.
>>
>
> Do the applications use implicit autocommit, or do they use explicit
> transaction blocks?
>
> --
> Death to <Redacted>, and butter sauce.
> Don't boil me, I'm still alive.
> <Redacted> lobster!
>

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