From a0b352a8b98ee28a7faba0ed7b8684bb0f9d273c Mon Sep 17 00:00:00 2001 From: Dean Rasheed Date: Sat, 18 Apr 2026 18:49:38 +0100 Subject: [PATCH v2] Fix expansion of virtual generated columns in EXCLUDED. If the SET or WHERE clause of an INSERT ... ON CONFLICT DO UPDATE contained references to virtual generated columns of the EXCLUDED pseudo-relation, they were not be properly expanded, leading to an error, or wrong results. The problem was that expand_virtual_generated_columns() would expand virtual generated columns in both the SET and WHERE clauses and in the targetlist of the EXCLUDED pseudo-relation. Then fix_join_expr() from set_plan_refs() would turn the expanded expressions in the SET and WHERE clauses back into Vars, because they would be found to match the entries in the indexed tlist produced from exclRelTlist. To prevent that from happening, do not expand virtual generated columns in the EXCLUDED pseudo-relation's targetlist. As a result, exclRelTlist now always contains only Vars -- something already claimed in a couple of existing comments in the planner, which relied on that to skip processing it (though those did not appear to constitute active bugs). Reported-by: Satyanarayana Narlapuram Author: Satyanarayana Narlapuram Author: Dean Rasheed Discussion: https://postgr.es/m/CAHg+QDf7wTLz_vqb1wi1EJ_4Uh+Vxm75+b4c-Ky=6P+yOAHjbQ@mail.gmail.com Backpatch-through: 18 --- src/backend/optimizer/prep/prepjointree.c | 19 ++++++++ .../regress/expected/generated_virtual.out | 48 +++++++++++++++++++ src/test/regress/sql/generated_virtual.sql | 25 ++++++++++ 3 files changed, 92 insertions(+) diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c index 95bf51606cc..4424fdbe906 100644 --- a/src/backend/optimizer/prep/prepjointree.c +++ b/src/backend/optimizer/prep/prepjointree.c @@ -501,6 +501,7 @@ expand_virtual_generated_columns(PlannerInfo *root, Query *parse, { List *tlist = NIL; pullup_replace_vars_context rvcontext; + List *save_exclRelTlist = NIL; for (int i = 0; i < tupdesc->natts; i++) { @@ -568,8 +569,26 @@ expand_virtual_generated_columns(PlannerInfo *root, Query *parse, /* * Apply pullup variable replacement throughout the query tree. + * + * We intentionally do not touch the EXCLUDED pseudo-relation's + * targetlist here. Various places in the planner assume that it + * contains only Vars, and we want that to remain the case. More + * importantly, we don't want setrefs.c to turn any expanded + * EXCLUDED.virtual_column expressions in other parts of the query + * back into Vars referencing the original virtual column, which + * set_plan_refs() would do if exclRelTlist contained matching + * expressions. */ + if (parse->onConflict) + { + save_exclRelTlist = parse->onConflict->exclRelTlist; + parse->onConflict->exclRelTlist = NIL; + } + parse = (Query *) pullup_replace_vars((Node *) parse, &rvcontext); + + if (parse->onConflict) + parse->onConflict->exclRelTlist = save_exclRelTlist; } return parse; diff --git a/src/test/regress/expected/generated_virtual.out b/src/test/regress/expected/generated_virtual.out index fc41c480d40..4eb5d5376d0 100644 --- a/src/test/regress/expected/generated_virtual.out +++ b/src/test/regress/expected/generated_virtual.out @@ -1723,3 +1723,51 @@ select * from gtest33 where b is null; reset constraint_exclusion; drop table gtest33; +-- Ensure that EXCLUDED. in INSERT ... ON CONFLICT +-- DO UPDATE is expanded to the generation expression, both for plain and +-- partitioned target relations. +create table gtest34 (id int primary key, a int, + c int generated always as (a * 10) virtual); +insert into gtest34 values (1, 5); +insert into gtest34 values (1, 7) + on conflict (id) do update set a = excluded.c returning *; + id | a | c +----+----+----- + 1 | 70 | 700 +(1 row) + +insert into gtest34 values (1, 2) + on conflict (id) do update set a = gtest34.c + excluded.c returning *; + id | a | c +----+-----+------ + 1 | 720 | 7200 +(1 row) + +insert into gtest34 values (1, 3) + on conflict (id) do update set a = 999 where excluded.c > 20 returning *; + id | a | c +----+-----+------ + 1 | 999 | 9990 +(1 row) + +drop table gtest34; +create table gtest34p (id int primary key, a int, + c int generated always as (a * 10) virtual) + partition by range (id); +create table gtest34p_1 partition of gtest34p for values from (1) to (100); +insert into gtest34p values (1, 5); +insert into gtest34p values (1, 7) + on conflict (id) do update set a = excluded.c returning *; + id | a | c +----+----+----- + 1 | 70 | 700 +(1 row) + +insert into gtest34p values (1, 2) + on conflict (id) do update set a = gtest34p.c + excluded.c returning *; + id | a | c +----+-----+------ + 1 | 720 | 7200 +(1 row) + +drop table gtest34p; diff --git a/src/test/regress/sql/generated_virtual.sql b/src/test/regress/sql/generated_virtual.sql index 9b32413e3a9..4f0c2d57c1f 100644 --- a/src/test/regress/sql/generated_virtual.sql +++ b/src/test/regress/sql/generated_virtual.sql @@ -906,3 +906,28 @@ select * from gtest33 where b is null; reset constraint_exclusion; drop table gtest33; + +-- Ensure that EXCLUDED. in INSERT ... ON CONFLICT +-- DO UPDATE is expanded to the generation expression, both for plain and +-- partitioned target relations. +create table gtest34 (id int primary key, a int, + c int generated always as (a * 10) virtual); +insert into gtest34 values (1, 5); +insert into gtest34 values (1, 7) + on conflict (id) do update set a = excluded.c returning *; +insert into gtest34 values (1, 2) + on conflict (id) do update set a = gtest34.c + excluded.c returning *; +insert into gtest34 values (1, 3) + on conflict (id) do update set a = 999 where excluded.c > 20 returning *; +drop table gtest34; + +create table gtest34p (id int primary key, a int, + c int generated always as (a * 10) virtual) + partition by range (id); +create table gtest34p_1 partition of gtest34p for values from (1) to (100); +insert into gtest34p values (1, 5); +insert into gtest34p values (1, 7) + on conflict (id) do update set a = excluded.c returning *; +insert into gtest34p values (1, 2) + on conflict (id) do update set a = gtest34p.c + excluded.c returning *; +drop table gtest34p; -- 2.51.0