Subject: pgsql: Repair commits 317aba70e et al for -DWRITE_READ_PARSE_PLAN_TREES

From: Tom Lane <[email-masked]>
Date: Thu, 13 Mar 2025 16:13:22 +0000

Repair commits 317aba70e et al for -DWRITE_READ_PARSE_PLAN_TREES.

Letting the rewriter keep RangeTblEntry.relid when expanding a view
RTE, without making the outfuncs/readfuncs changes that went along
with that originally, is more problematic than I realized.  It causes
WRITE_READ_PARSE_PLAN_TREES testing to fail because outfuncs/readfuncs
don't think relid need be saved in an RTE_SUBQUERY RTE.

There doesn't seem to be any other good route to fixing the whole-row
Var problem solved at f4e7756ef, so we just have to deal with the
consequences.  We can make the eventually-produced plan tree safe
for WRITE_READ_PARSE_PLAN_TREES by clearing the relid field at the
end of planning, as was already being done for the functions field.
(The functions field is not problematic here because our abuse of it
is strictly local to the planner.)  However, there is no nice fix for
the post-rewrite WRITE_READ_PARSE_PLAN_TREES test.

The solution adopted here is to remove the post-rewrite test in the
affected branches.  That's surely less than ideal, but a couple of
arguments can be made why it's not unacceptable.  First, the behavior
of outfuncs/readfuncs for parsetrees in these branches is frozen no
matter what, because of catalog stability requirements.  So we're not
testing anything that is going to change.  Second, testing
WRITE_READ_PARSE_PLAN_TREES at this particular time doesn't correspond
to any direct system functionality requirement, neither rule storage
nor plan transmission.

Reported-by: Andres Freund <[email-masked]>
Author: Tom Lane <[email-masked]>
Reviewed-by: Dean Rasheed <[email-masked]>
Discussion: https://postgr.es/m/[email-masked]
Backpatch-through: 13-15

Branch
------
REL_14_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/1a20bc94623e6ee5041713fc66b7f803832f0bba

Modified Files
--------------
src/backend/optimizer/plan/setrefs.c |  9 ++++++++
src/backend/rewrite/rewriteHandler.c |  4 ++--
src/backend/tcop/postgres.c          | 43 ++++--------------------------------
src/include/nodes/parsenodes.h       |  4 ++--
4 files changed, 17 insertions(+), 43 deletions(-)