Horton

Re: Support "Right Semi Join" plan shapes

wenhui qiu <qiuwenhuifx@gmail.com>

View thread
From: wenhui qiu <qiuwenhuifx@gmail.com>
To: Alena Rybakina <lena.ribackina@yandex.ru>
Cc: Richard Guo <guofenglinux@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>, vignesh C <vignesh21@gmail.com>
Date: 2024-02-08T05:50:17Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Support "Right Semi Join" plan shapes

  2. Fix neqjoinsel's behavior for semi/anti join cases.

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.ribackina@yandex.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
>
>