On Tue, Nov 3, 2026 at 8:58 AM Manu <[email protected]> wrote:
> - float4, float8, then extra_float_digits = 0: stale / stale / stale,
> since float8out is still IMMUTABLE in 18 and 19; on master it is
> STABLE now, and there v5 rejects them
True for scalars, but accepting arrays of them here is new in 19.
18 rejects every array here; 19 recurses into the element type, and on
REL_19_STABLE
float4out, float8out, byteaout and the geometric output functions are
still IMMUTABLE (e75fcc9867fd made them STABLE on master only [1]). So
19 with v5 accepts float4[], float8[], bytea[], point[] etc., and the
index goes stale:
create table t (f float8[]);
insert into t values ('{0.30000000000000004}');
create index t_i on t ((json_array(f returning jsonb)));
set extra_float_digits = 0;
set enable_seqscan = off;
select count(*) from t where json_array(f returning jsonb) = '[[0.3]]';
On REL_19_STABLE 4b1abd678223 with v5 the index scan returns 0, a seq
scan returns 1. 18.6 rejects the CREATE INDEX. bytea[] with
bytea_output = escape behaves the same.
AI found this while testing v5 and prepared the attached patch; I
haven't manually reviewed the code yet. It is for REL_19_STABLE only,
on top of v5: arrays of float4, float8, bytea and the geometric types,
or of domains over them, are mutable. Scalars keep the 18 behavior, so
existing schemas still restore. Master doesn't need it, there v5
already rejects all of these. The file name starts with nocfbot so
cfbot keeps testing v5.
Tested on REL_19_STABLE 4b1abd678223 + v5 + this patch, assertions
on: the regress suite passes; without the jsonfuncs.c hunk the new
sqljson test fails. On master b6178c942ea7 + v5, the same statements
are rejected already.
[1]
https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=e75fcc9867fdfe295957ad5c9a98cbe2e1b4c5c3
Nik
From 578715b04bac60038011685d1fbb586e135f8d45 Mon Sep 17 00:00:00 2001
From: Nik Samokhvalov <[email protected]>
Date: Tue, 3 Nov 2026 19:14:34 -0800
Subject: [PATCH] Treat arrays of setting-dependent types as mutable in JSON
(19)
On REL_19_STABLE float4out, float8out, byteaout and the geometric
output functions are still marked IMMUTABLE, although their output
depends on extra_float_digits or bytea_output. On master they are
STABLE since e75fcc9867f, which was not backpatched, so there
json_check_mutability() already treats these types as mutable.
18 rejected every array in SQL/JSON constructors used in an index
expression. Since ecd9288624a, 19 recurses into the element type and
accepts arrays of these types, and such an index returns wrong results
after the setting changes. Treat arrays of them, and of domains over
them, as mutable on 19. Scalars keep the 18 behavior, so existing
schemas still restore.
This is for REL_19_STABLE only, on top of the v5 series. Master does
not need it.
Discussion: [email protected]">https://postgr.es/m/[email protected]
---
src/backend/utils/adt/jsonfuncs.c | 38 ++++++++++++++++++++++++---
src/test/regress/expected/sqljson.out | 32 ++++++++++++++++++++++
src/test/regress/sql/sqljson.sql | 15 +++++++++++
3 files changed, 82 insertions(+), 3 deletions(-)
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 82b16d6f150..7908331ab71 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -6088,6 +6088,34 @@ json_categorize_type(Oid typoid, bool is_jsonb,
}
}
+/*
+ * Does the output of this built-in type depend on extra_float_digits or
+ * bytea_output? On master the output functions of these types are STABLE,
+ * so the generic check below already treats them as mutable. In 19 they
+ * are still marked IMMUTABLE. 18 accepted them as scalars, so keep that,
+ * but do not newly accept arrays of them: 18 rejected every array.
+ */
+static bool
+json_output_depends_on_settings(Oid typoid)
+{
+ switch (typoid)
+ {
+ case FLOAT4OID:
+ case FLOAT8OID:
+ case BYTEAOID:
+ case POINTOID:
+ case LSEGOID:
+ case PATHOID:
+ case BOXOID:
+ case POLYGONOID:
+ case LINEOID:
+ case CIRCLEOID:
+ return true;
+ default:
+ return false;
+ }
+}
+
/*
* Check whether a type conversion to JSON or JSONB involves any mutable
* functions. This recurses into container types (arrays, ranges, multiranges,
@@ -6160,10 +6188,14 @@ json_check_mutability(Oid typoid, bool *has_mutable)
* Elements of a user-defined base type are printed through a cast
* to json if one exists, looked up at run time, so creating or
* dropping that cast later changes the output. Treat such arrays
- * as mutable, like user-defined ranges; otherwise recurse into the
- * element type.
+ * as mutable, like user-defined ranges; otherwise recurse into
+ * the element type. Arrays of the types listed in
+ * json_output_depends_on_settings() are mutable too.
*/
- if (getBaseType(att_typelem) >= FirstNormalObjectId)
+ Oid elembase = getBaseType(att_typelem);
+
+ if (elembase >= FirstNormalObjectId ||
+ json_output_depends_on_settings(elembase))
*has_mutable = true;
else
json_check_mutability(att_typelem, has_mutable);
diff --git a/src/test/regress/expected/sqljson.out b/src/test/regress/expected/sqljson.out
index f5f1056de74..3e4ef1c4b42 100644
--- a/src/test/regress/expected/sqljson.out
+++ b/src/test/regress/expected/sqljson.out
@@ -1519,6 +1519,38 @@ drop type mytext_t cascade;
NOTICE: drop cascades to 2 other objects
DETAIL: drop cascades to function mytext_t_in(cstring)
drop cascades to function mytext_t_out(mytext_t)
+-- Arrays of types whose output depends on extra_float_digits or bytea_output
+-- are mutable; 18 rejected them. Scalars of these types stay accepted.
+create domain d_float8 as float8;
+create table test_setting_array(f4 float4[], f8 float8[], df d_float8[],
+ b bytea[], p point[], s float8);
+create index on test_setting_array(json_array(f4 returning jsonb)); -- error
+ERROR: functions in index expression must be marked IMMUTABLE
+LINE 1: create index on test_setting_array(json_array(f4 returning j...
+ ^
+create index on test_setting_array(json_array(f8 returning jsonb)); -- error
+ERROR: functions in index expression must be marked IMMUTABLE
+LINE 1: create index on test_setting_array(json_array(f8 returning j...
+ ^
+create index on test_setting_array(json_array(df returning jsonb)); -- error
+ERROR: functions in index expression must be marked IMMUTABLE
+LINE 1: create index on test_setting_array(json_array(df returning j...
+ ^
+create index on test_setting_array(json_array(b returning jsonb)); -- error
+ERROR: functions in index expression must be marked IMMUTABLE
+LINE 1: create index on test_setting_array(json_array(b returning js...
+ ^
+create index on test_setting_array(json_array(p returning jsonb)); -- error
+ERROR: functions in index expression must be marked IMMUTABLE
+LINE 1: create index on test_setting_array(json_array(p returning js...
+ ^
+create index on test_setting_array(json_object('key' value f8 returning jsonb)); -- error
+ERROR: functions in index expression must be marked IMMUTABLE
+LINE 1: create index on test_setting_array(json_object('key' value f...
+ ^
+create index on test_setting_array(json_array(s returning jsonb)); -- ok
+drop table test_setting_array;
+drop domain d_float8;
-- IS JSON predicate
SELECT NULL IS JSON;
?column?
diff --git a/src/test/regress/sql/sqljson.sql b/src/test/regress/sql/sqljson.sql
index f32b5def1ed..899d1245598 100644
--- a/src/test/regress/sql/sqljson.sql
+++ b/src/test/regress/sql/sqljson.sql
@@ -590,6 +590,21 @@ drop table test_base_array;
drop domain d_mytext_t;
drop type mytext_t cascade;
+-- Arrays of types whose output depends on extra_float_digits or bytea_output
+-- are mutable; 18 rejected them. Scalars of these types stay accepted.
+create domain d_float8 as float8;
+create table test_setting_array(f4 float4[], f8 float8[], df d_float8[],
+ b bytea[], p point[], s float8);
+create index on test_setting_array(json_array(f4 returning jsonb)); -- error
+create index on test_setting_array(json_array(f8 returning jsonb)); -- error
+create index on test_setting_array(json_array(df returning jsonb)); -- error
+create index on test_setting_array(json_array(b returning jsonb)); -- error
+create index on test_setting_array(json_array(p returning jsonb)); -- error
+create index on test_setting_array(json_object('key' value f8 returning jsonb)); -- error
+create index on test_setting_array(json_array(s returning jsonb)); -- ok
+drop table test_setting_array;
+drop domain d_float8;
+
-- IS JSON predicate
SELECT NULL IS JSON;
SELECT NULL IS NOT JSON;
base-commit: 4b1abd678223ab22e1fe245547bf5b4a91db56ee
prerequisite-patch-id: 35205c44ccc706b9e6ac34241ef02a0fe5ec85db
prerequisite-patch-id: 136b0fa329b0ae83c6027f44afb8d63aa47e7678
--
2.50.1 (Apple Git-155)
