Re: pgsql: Modify tqueue infrastructure to support transient record types.

On Sat, Nov 7, 2015 at 3:29 AM, Robert Haas <rhaas@postgresql.org> wrote:
>
> Modify tqueue infrastructure to support transient record types.
>

+static HeapTuple
+gather_readnext(GatherState *gatherstate)
+{
..
+       if (readerdone)
+       {
+           DestroyTupleQueueReader(reader);
+           --gatherstate->nreaders;
+           if (gatherstate->nreaders == 0)
+           {
+               ExecShutdownGather(gatherstate);
+               return NULL;
+           }
..
}

I think after readers are done, it's not good to call ShutdownGather,

because it will destroy the parallel context as well and the same is

needed for the cases when after the readers are done we still need

to access dsm, like for rescan and for scanning the data from local

node.

Here, we should just shutdown the workers and that is what we were

doing previous to this commit.  Attached patch fixes this problem.