Re: fix cost subqueryscan wrong parallel cost

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

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

To: "David G. Johnston" <david.g.johnston@gmail.com>

Cc: Robert Haas <robertmhaas@gmail.com>, Richard Guo <guofenglinux@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>

Date: 2022-04-29T19:38:03Z

Lists: pgsql-hackers

Attachments

change-cost_subqueryscan-rowcount-estimate-2.patch (text/x-diff) patch

I wrote:
> So perhaps we should do it more like the attached, which produces
> this plan for the UNION case:

sigh ... actually attached this time.

			regards, tom lane

Commits

Fix rowcount estimate for SubqueryScan that's under a Gather.
- c40ba5f318f9 15.0 landed
Optimize order of GROUP BY keys
- db0d67db2401 15.0 cited