Re: BUG #15225: [XX000] ERROR: invalid DSA memory alloc request size 1073741824 / Where: parallel worker

Hi Dilip,

That should not be possible; nothing else is using the DB on that machine
as it is my development machine.

On Wed, Jun 6, 2018 at 6:53 PM Dilip Kumar <dilipbalaut(at)gmail(dot)com> wrote:

> On Wed, Jun 6, 2018 at 3:45 PM, Frits Jalvingh <jal(at)etc(dot)to> wrote:
>
>> Hi Thomas,
>>
>> I know that the message is about running out of memory, I just meant to
>> say that it is a different message than before. Which led me to think that
>> this might be another issue. But of course OOM can occur at many places and
>> that might explain the different messages.
>>
>> As far as that explain thing goes, the odd thing seems to be that
>> /without/ the explain the database uses a non parallel plan. If I execute
>> the exact same statement without explain I see one postgres process running
>> at 100% for a long time, then it produces its output proper.
>>
>> If I add the explain part to it I see three processes: the main process
>> handling the EXPLAIN and two parallel workers. So the issue is that the
>> explain plan actually uses another plan than the same statement without
>> explain(!). This also explains the OOM, because indeed I see all processes
>> gobble up memory like mad, growing to 12GB each and then it dies.
>>
>
> There is also possiblility that it might have planned to use parallel
> worker (which is shown in explain )but during actual execution it has not
> got any free background worker (other parallel sessions might be using all
> the workers).
>
> --
> Regards,
> Dilip Kumar
> EnterpriseDB: http://www.enterprisedb.com
>