Re: Reference to - BUG #18349: ERROR: invalid DSA memory alloc request size 1811939328, CONTEXT: parallel worker

Andrei Lepikhov <lepihov@gmail.com>

From: Andrei Lepikhov <lepihov@gmail.com>
To: Thomas Munro <thomas.munro@gmail.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Craig Milhiser <craig@milhiser.com>, pgsql-bugs@lists.postgresql.org
Date: 2024-10-17T09:48:40Z
Lists: pgsql-bugs
On 10/17/24 15:57, Thomas Munro wrote:
> On Thu, Oct 17, 2024 at 9:12 PM Andrei Lepikhov <lepihov@gmail.com> wrote:
>> Yeah, I misunderstood the meaning of the estimated_size variable. Your
>> solution is more universal. Also, I confirm, it passes my synthetic  test.
>> Also, it raises the immediate question: What if we have too many
>> duplicates? Sometimes, in user complaints, I see examples where they,
>> analysing the database's logical consistency, pass through millions of
>> duplicates to find an unexpected value. Do we need a top memory
>> consumption limit here? I recall a thread in the mailing list with a
>> general approach to limiting backend memory consumption, but it is
>> finished with no result.
> 
> It is a hard problem alright[1].
> 
>> The patch looks good as well as commentary.
> 
> Thanks, I will go ahead and push this now.
> 
> [1] https://www.postgresql.org/message-id/flat/CAAKRu_aLMRHX6_y%3DK5i5wBMTMQvoPMO8DT3eyCziTHjsY11cVA%40mail.gmail.com
Thanks for the link.
BTW, why not to use current case and fix the problem with the 'invalid 
DSA memory alloc request size 1811939328' itself ?

-- 
regards, Andrei Lepikhov




Commits

  1. Fix extreme skew detection in Parallel Hash Join.