From 26cfe11c9487d53982c903d929d9686fecf04911 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Sat, 9 Sep 2023 14:53:24 -0400 Subject: [PATCH v1 3/3] Preprocess column DEFAULT expressions before checking volatility. The previous coding skipped the preprocessing step and thus had (at least) two failure modes: it could fail to notice the use of a volatile function default-argument expression, or it could reject a polymorphic function that is actually immutable on the datatype of interest. The latter would just result in an unnecessary table rewrite, but the former could allow the attmissingval functionality to be used in a case where it should not be. Noted while investigating bug #18097 from Jim Keener. Back-patch to all supported versions. Discussion: https://postgr.es/m/18097-ebb179674f22932f@postgresql.org --- src/backend/catalog/heap.c | 2 +- src/test/regress/expected/fast_default.out | 18 ++++++++++++++++++ src/test/regress/sql/fast_default.sql | 11 +++++++++++ 3 files changed, 30 insertions(+), 1 deletion(-) diff --git a/src/backend/catalog/heap.c b/src/backend/catalog/heap.c index 9b7544e9b7..b44a4c96bb 100644 --- a/src/backend/catalog/heap.c +++ b/src/backend/catalog/heap.c @@ -2365,7 +2365,7 @@ AddRelationNewConstraints(Relation rel, continue; /* If the DEFAULT is volatile we cannot use a missing value */ - if (colDef->missingMode && contain_volatile_functions((Node *) expr)) + if (colDef->missingMode && ContainVolatileFunctions((Expr *) expr)) colDef->missingMode = false; defOid = StoreAttrDefault(rel, colDef->attnum, expr, is_internal, diff --git a/src/test/regress/expected/fast_default.out b/src/test/regress/expected/fast_default.out index 91f25717b5..59365dad96 100644 --- a/src/test/regress/expected/fast_default.out +++ b/src/test/regress/expected/fast_default.out @@ -272,7 +272,25 @@ SELECT comp(); Rewritten (1 row) +-- check that we notice insertion of a volatile default argument +CREATE FUNCTION foolme(timestamptz DEFAULT clock_timestamp()) + RETURNS timestamptz + IMMUTABLE AS 'select $1' LANGUAGE sql; +ALTER TABLE T ADD COLUMN c3 timestamptz DEFAULT foolme(); +NOTICE: rewriting table t for reason 2 +SELECT attname, atthasmissing, attmissingval FROM pg_attribute + WHERE attrelid = 't'::regclass AND attnum > 0 + ORDER BY attnum; + attname | atthasmissing | attmissingval +---------+---------------+--------------- + pk | f | + c1 | f | + c2 | f | + c3 | f | +(4 rows) + DROP TABLE T; +DROP FUNCTION foolme(timestamptz); -- Simple querie CREATE TABLE T (pk INT NOT NULL PRIMARY KEY); SELECT set('t'); diff --git a/src/test/regress/sql/fast_default.sql b/src/test/regress/sql/fast_default.sql index 16a3b7ca51..dc9df78a35 100644 --- a/src/test/regress/sql/fast_default.sql +++ b/src/test/regress/sql/fast_default.sql @@ -256,7 +256,18 @@ ALTER TABLE T ADD COLUMN c2 TIMESTAMP DEFAULT clock_timestamp(); SELECT comp(); +-- check that we notice insertion of a volatile default argument +CREATE FUNCTION foolme(timestamptz DEFAULT clock_timestamp()) + RETURNS timestamptz + IMMUTABLE AS 'select $1' LANGUAGE sql; +ALTER TABLE T ADD COLUMN c3 timestamptz DEFAULT foolme(); + +SELECT attname, atthasmissing, attmissingval FROM pg_attribute + WHERE attrelid = 't'::regclass AND attnum > 0 + ORDER BY attnum; + DROP TABLE T; +DROP FUNCTION foolme(timestamptz); -- Simple querie CREATE TABLE T (pk INT NOT NULL PRIMARY KEY); -- 2.39.3