Message-ID: <eca91527-07a8-42d6-b4d6-7cf75b946dd7@cleistech.it>
Date: Mon, 13 Jan 2025 17:59:32 +0100
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Subject: Re: Intermittent errors when fetching cursor rows on PostgreSQL 16
To: Adrian Klaver <adrian.klaver@aklaver.com>,
 pgsql-general@lists.postgresql.org
Cc: Massimo Catti <mcatti@cleistech.it>, Livio Pizzolo <lpizzolo@cleistech.it>
References: <446423eb-4a4e-4135-bbb8-4d0e5c7aac3b@cleistech.it>
 <25d5fb16-9bb2-4ad1-969c-eaca03ccbaaf@aklaver.com>
 <6ce80aaa-970b-4432-938a-39a07f811599@cleistech.it>
 <9f60eb26-7d34-4228-bd78-74c6deb90e54@aklaver.com>
 <282c2a48-bb12-4486-b03d-563523cac81b@cleistech.it>
 <2645a89e-d661-4f2b-92b3-01154a78d535@aklaver.com>
 <e2332684-8d0f-47ba-a5ef-5b2b9c9f8cf0@cleistech.it>
 <54689a6a-839c-44c4-90b5-b9692e8e7cb0@aklaver.com>
 <4efe42a2-789c-4957-a564-25199869f6ec@cleistech.it>
 <e906a6a1-e97d-4bf7-afe3-21a430b3a944@aklaver.com>
 <ec5ce003-6ad9-4cfd-8186-6ca66f285ad3@cleistech.it>
 <b5e32ab4-2187-45f0-b360-47f82d481ff8@aklaver.com>
 <382a1eec-2069-4010-bbdb-37260a1a53a7@cleistech.it>
 <cdfa3e0c-a5cc-4f29-bcb7-72056ae03f1e@aklaver.com>
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From: Enrico Schenone <eschenone@cleistech.it>
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Il 13/01/25 17:19, Adrian Klaver ha scritto:
> On 1/13/25 00:45, Enrico Schenone wrote:
>> Hello, Adrian.
>> As I said days ago, I have arranged a kind of stress test in=20
>> production environment.
>> I wrote a program that loads a temporary table, loads 2049 rows into=20
>> them from a baseline_table and finally declare two nested cursors.
>> The first cursor is on the temp table as parent while the second is=20
>> on a lookup table as child.
>>
>> The program logic is the transposition of one fragment of several=20
>> production programs that was failing on cursors, and has to be=20
>> intended as a POC only.
>>
>
>
>> And Well, I'm quite confused: no error at all has been detected, not=20
>> only on the test programs but in the whole production system. The=20
>> error was completely disappeared.
>>
>> Then I have stopped the four tasks of the stress test leaving all=20
>> other services running for a week, and again no error at all.
>>
>> No setup was changed nor servers was rebooted, nor infrastructure has=20
>> been upgraded during the test period.
>
> You are absolutely sure about the above?
I can say Yes. All test operations has been logged and verified against=20
the Postgresql log.
The only component not under my control is the Provider's=20
Infrastructure, but=C2=A0 the infrastructure admin ensured me that no=20
operation at all has been made. I beleave him because it is a reliable=20
tecnician end a well known person.
>
>>
>> As a result, at the moment I'm not understood not only Why & Where=20
>> the error was occurring, but also Why it is disappeared.
>
> Errors that 'fix' themselves are the most frustrating kind, as you=20
> know in the back of your mind they will likely pop up again.
True, knocking again to my door ... I still can't beleave.
>
>>
>> Anyone may feel free to give me his opinion.
>> For the moment I'll make no other test unless the error is knocking=20
>> back to my door.
>
> That is all you can do.
>
>>
>> *Enrico Schenone*
>> Software Architect
>>
>
Thanks a lot for your interest in sharing my strange experience.
Best regards.
Enrico

*Enrico Schenone*
Software Architect