Re: What happens if tuple queue is full

On Wed, Jul 6, 2016 at 10:57 AM, Tatsuo Ishii <ishii@postgresql.org> wrote:
> Hi,
>
> Does anybody know what will happen if tuple queue is full, which is
> used by the parallel leader and workers? In my understanding memory
> used for the queue is a dynamic shared memory and it could be full.

The queue can gets full in the case where the leader is processing is slow
than the worker is producing tuples. In those scenarios, the worker waits
until the the queue gets empty to place the new satisfied record.The worker
gets awaken whenever the leader finishes reading the data from queue.


Regards,
Hari Babu
Fujitsu Australia