Re: Significant Execution Time Difference Between PG13.14 and PG16.4 for Query on information_schema Tables.

Richard Guo <guofenglinux@gmail.com>

From: Richard Guo <guofenglinux@gmail.com>

To: Tom Lane <tgl@sss.pgh.pa.us>

Cc: David Rowley <dgrowleyml@gmail.com>, nikhil raj <nikhilraj474@gmail.com>, pgsql-hackers@lists.postgresql.org

Date: 2024-08-29T01:54:57Z

Lists: pgsql-hackers, pgsql-general

On Thu, Aug 29, 2024 at 4:47 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> In the meantime, I think this test case is mighty artificial,
> and it wouldn't bother me any to just take it out again for the
> time being.

Yeah, I think we can remove the 't1.two+t2.two' test case if we go
with your proposed patch to address this performance regression.

Thanks
Richard

Commits

Avoid inserting PlaceHolderVars in cases where pre-v16 PG did not.
- b43110869fd8 17.0 landed
- 80d9c07a4a8c 16.5 landed
- cb8e50a4a09f 18.0 landed
Remove one memoize test case added by commit 069d0ff02.
- 3409b4db631f 18.0 landed