Re: Oversight in reparameterize_path_by_child leading to executor crash

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

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

To: Richard Guo <guofenglinux@gmail.com>

Cc: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>

Date: 2023-08-22T15:43:29Z

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 →

Postpone reparameterization of paths until create_plan().
- b7e2121ab7d6 17.0 landed
Apply band-aid fix for an oversight in reparameterize_path_by_child.
- e031995d5c26 14.11 landed
- 7af96a66f43c 13.14 landed
- 62f120203147 16.2 landed
- 2e822a1d62d0 12.18 landed
- 12ec16d11c8b 15.6 landed

Attachments

v6-0001-Dont-reparameterize-sample-scans.patch (text/x-diff) patch v6-0001

I wrote:
> ... I think the risk/reward ratio for messing with this in the
> back branches is unattractive in any case: to fix a corner case that
> apparently nobody uses in the field, we risk breaking any number of
> mainstream parameterized-path cases.  I'm content to commit the v5 patch
> (or a successor) into HEAD, but at this point I'm not sure I even want
> to risk it in v16, let alone perform delicate surgery to get it to work
> in older branches.  I think we ought to go with the "tablesample scans
> can't be reparameterized" approach in v16 and before.

Concretely, about like this for v16, and similarly in older branches.

			regards, tom lane