Re: [HACKERS] SERIALIZABLE with parallel query

On Thu, Feb 22, 2018 at 10:35 PM, Robert Haas <robertmhaas@gmail.com> wrote:
> On Thu, Feb 22, 2018 at 7:54 AM, Thomas Munro
>> PS  I noticed that for BecomeLockGroupMember() we say "If we can't
>> join the lock group, the leader has gone away, so just exit quietly"
>> but for various other similar things we spew errors (most commonly
>> seen one being "ERROR:  could not map dynamic shared memory segment").
>> Intentional?
>
> I suppose I thought that if we failed to map the dynamic shared memory
> segment, it might be down to any one of several causes; whereas if we
> fail to join the lock group, it must be because the leader has already
> exited.  There might be a flaw in that thinking, though.
>

By the way, in which case leader can exit early?  As of now, we do
wait for workers to end both before the query is finished or in error
cases.

-- 
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com