EXPLAIN ... FOR PORTION OF should not evaluate bounds

Started by Paul A Jungwirth17 days ago2 messageshackers
Beta feature

Hackorum builds and tests every patch posted to the lists, not only commitfest submissions. This is Hackorum's own CI rather than the PostgreSQL project's, and it is still under testing - please report anything that looks wrong.

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This thread has been committed, so CI has stopped here. Anything below is the last result it produced.

You can run a PostgreSQL built from this patch straight from Docker, with no checkout and no build:

docker run --rm -p 5432:5432 ghcr.io/hackorum-dev/postgres-patch:t253670
psql -h localhost -U postgres

Built from patchset v1 (message #1), September 08, 2026 at 03:07 AM.

Every patchset is also pushed to a branch of our PostgreSQL fork, so you can check out the same tree CI built. Without a PostgreSQL checkout:

git clone --branch t253670_1 https://github.com/hackorum-dev/postgres.git

In a checkout you already have, add the fork once:

git remote add hackorum https://github.com/hackorum-dev/postgres.git

then, for this patchset and every later one:

git fetch hackorum t253670_1 && git checkout t253670_1

Patchset v1 (message #1) is on t253670_1

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#1Paul A Jungwirth
pj@illuminatedcomputing.com

Hi Hackers,

Here is a fix for findings D3 & D4 & D10 from [0]/messages/by-id/CA+renyV6QLOJYmLo3gbsg1Y+Crho8NqME1jJXgPbO_NgxfBaKQ@mail.gmail.com.

The issue is that we evaluate FOR PORTION OF bounds even under
EXPLAIN. This causes various problems, like failing on `EXPLAIN
(GENERIC PLAN)`, failing on `FOR PORTION OF (null)`, and calling
functions for the bounds (beyond selectivity estimation). To fix it,
we add a guard for EXEC_FLAG_EXPLAIN_ONLY.

[0]: /messages/by-id/CA+renyV6QLOJYmLo3gbsg1Y+Crho8NqME1jJXgPbO_NgxfBaKQ@mail.gmail.com

Yours,

--
Paul ~{:-)
pj@illuminatedcomputing.com

Attachments:

t253670_1
v1-0001-Don-t-evaluate-the-FOR-PORTION-OF-target-under-EX.patchtext/x-patch; charset=US-ASCII; name=v1-0001-Don-t-evaluate-the-FOR-PORTION-OF-target-under-EX.patchDownload+152-18
#2Peter Eisentraut
peter_e@gmx.net
In reply to: Paul A Jungwirth (#1)
Re: EXPLAIN ... FOR PORTION OF should not evaluate bounds

On 04.09.26 06:43, Paul A Jungwirth wrote:

Here is a fix for findings D3 & D4 & D10 from [0].

The issue is that we evaluate FOR PORTION OF bounds even under
EXPLAIN. This causes various problems, like failing on `EXPLAIN
(GENERIC PLAN)`, failing on `FOR PORTION OF (null)`, and calling
functions for the bounds (beyond selectivity estimation). To fix it,
we add a guard for EXEC_FLAG_EXPLAIN_ONLY.

[0] /messages/by-id/CA+renyV6QLOJYmLo3gbsg1Y+Crho8NqME1jJXgPbO_NgxfBaKQ@mail.gmail.com

committed