Re: parallelize queries containing initplans

On Mon, Oct 30, 2017 at 10:07 AM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> On Mon, Oct 30, 2017 at 9:00 AM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>> Now that the PARAM_EXTERN issue is fixed, I have rebased this patch.
>> This patch had been switched to Ready For Committer in last CF, then
>> Robert had comments which I have addressed, so I think the status
>> should be switched back to Ready For committer. Let me know if you
>> think it should be switched to some other status.
>
> The change to ExplainPrintPlan doesn't look good to me, because it
> actually moves the initPlan; I don't think it's good for EXPLAIN to
> mutate the plan state tree. It should find a way to display the
> results *as if* the initPlans were attached to the subnode, but
> without actually moving them.
>

Actually, with the latest patch, we don't need these changes in
ExplainPrintPlan. Earlier, we need these changes because the patch
had changed SS_charge_for_initplans to mark the path with initplan as
parallel safe. However, after removing that change in the previous
version of patch [1], this is not required as now we won't add gather
on top plan node having initplan.

[1] - https://www.postgresql.org/message-id/CAA4eK1JD%3DpJYBn8rN5RimiEVtPJmVNmyq5p6VoZBnUw2xRYB7w%40mail.gmail.com
--
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com