RE: Determine parallel-safety of partition relations for Inserts

[Huang, Qiuyan]

Hi,

I notice the comment 5) about is_parallel_possible_for_modify() seems to be 
inaccurate in clauses.c.
        *  5) the reloption parallel_dml_enabled is not set for the target table

Because you have set parallel_dml_enabled to 'true' as default. 
        {
                {
                        "parallel_dml_enabled",
                        "Enables \"parallel dml\" feature for this table",
                        RELOPT_KIND_HEAP | RELOPT_KIND_PARTITIONED,
                        ShareUpdateExclusiveLock
                },
                true
        }

So even user doesn't set parallel_dml_enabled explicit, its value is 'on', 
Parallel is also possible for this rel(when enable_parallel_dml is on). 

Maybe we can just comment like this or a better one you'd like if you agree 
with above:
        *  5) the reloption parallel_dml_enabled is set to off

Regards
Huang

> -----Original Message-----
> From: Hou, Zhijie <houzj.f...@cn.fujitsu.com>
> Sent: Wednesday, February 3, 2021 9:01 AM
> To: Greg Nancarrow <gregn4...@gmail.com>
> Cc: Amit Kapila <amit.kapil...@gmail.com>; PostgreSQL Hackers
> <pgsql-hackers@lists.postgresql.org>; vignesh C <vignes...@gmail.com>;
> Amit Langote <amitlangot...@gmail.com>; David Rowley
> <dgrowle...@gmail.com>; Tom Lane <t...@sss.pgh.pa.us>; Tsunakawa,
> Takayuki/綱川 貴之 <tsunakawa.ta...@fujitsu.com>
> Subject: RE: Determine parallel-safety of partition relations for Inserts
> 
> Hi,
> 
> Attaching v5 patches with the changes:
>   * rebase the code on the greg's latest parallel insert patch
>   * fix some code style.
> 
> Please consider it for further review.
> 
> Best regards,
> Houzj
> 
> 
> 
>