Re: An inefficient query caused by unnecessary PlaceHolderVar

Richard Guo <guofenglinux@gmail.com>

From: Richard Guo <guofenglinux@gmail.com>

To: Andrei Lepikhov <lepihov@gmail.com>

Cc: Dmitry Dolgov <9erthalion6@gmail.com>, James Coleman <jtc331@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>

Date: 2024-12-09T12:20:16Z

Lists: pgsql-hackers

On Tue, Dec 3, 2024 at 5:33 PM Andrei Lepikhov <lepihov@gmail.com> wrote:
> A couple of words about your patch. These few lines of code caused a lot
> of discoveries, but in my opinion, they look fine. But I didn't find
> negative tests, where we need to wrap a Var with PHV like the following:

Pushed after adding two negative tests.  Thank you for your review.

Thanks
Richard

Commits

Avoid unnecessary wrapping for Vars and PHVs
- f64ec81a810e 18.0 landed
Avoid mislabeling of lateral references, redux.
- e032e4c7ddd0 18.0 cited
Avoid inserting PlaceHolderVars in cases where pre-v16 PG did not.
- cb8e50a4a09f 18.0 cited