Re: Parallel Seq Scan

On Thu, Oct 15, 2015 at 6:32 PM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>
wrote:
> On Wed, Oct 14, 2015 at 3:29 AM, Robert Haas <robertmhaas(at)gmail(dot)com>
wrote:
> I think this got messed up while rebasing on top of Gather node
> changes, but nonetheless, I have changed it such that PartialSeqScan
> node handling is after SeqScan.

Currently, the explain analyze of parallel seq scan plan is not showing the
allocated number of workers
including the planned workers.I feel this information is good for users in
understanding the performance
difference that is coming with parallel seq scan. It may be missed in
recent patch series. It was discussed
in[1].

Currently there is no qualification evaluation at Result and Gather nodes,
because of this reason, if any
query that contains any parallel restricted functions is not chosen for
parallel scan. Because of
this reason, there is no difference between parallel restricted and
parallel unsafe functions currently.
Is it fine for first version?

[1]
http://www.postgresql.org/message-id/CA+TgmobhQ0_+YObMLbJexvt4QEf6XbLfUdaX1OwL-ivgaN5qxw@mail.gmail.com

Regards,
Hari Babu
Fujitsu Australia