Re: Support "Right Semi Join" plan shapes

HI Richard
Now it is starting the last commitfest for v17, can you respond to
Alena Rybakina points?

Regards

On Thu, 8 Feb 2024 at 13:50, wenhui qiu <qiuwenhuifx(at)gmail(dot)com> wrote:

> Hi Alena Rybakina
> I saw this code snippet also disable mergejoin ,I think it same effect
> + /*
> + * For now we do not support RIGHT_SEMI join in mergejoin.
> + */
> + if (jointype == JOIN_RIGHT_SEMI)
> + {
> + *mergejoin_allowed = false;
> + return NIL;
> + }
> +
>
> Regards
>
> Alena Rybakina <lena(dot)ribackina(at)yandex(dot)ru> 于2024年1月30日周二 14:51写道：
>
>> Hi! Thank you for your work on this subject.
>>
>> I have reviewed your patch and I think it is better to add an Assert for
>> JOIN_RIGHT_SEMI to the ExecMergeJoin and ExecNestLoop functions to
>> prevent the use of RIGHT_SEMI for these types of connections (NestedLoop
>> and MergeJoin).
>> Mostly I'm suggesting this because of the set_join_pathlist_hook
>> function, which is in the add_paths_to_joinrel function, which allows
>> you to create a custom node. What do you think?
>>
>> --
>> Regards,
>> Alena Rybakina
>> Postgres Professional: http://www.postgrespro.com
>> The Russian Postgres Company
>>
>>