Movatterモバイル変換

[0]ホーム
URL:

Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

 Sign up
Appearance settings

Commite1fd61c

Browse files
committed
Ensure casting to typmod -1 generates a RelabelType.
Fix the code changed by commit5c056b0 so that we always generateRelabelType, not something else, for a cast to unspecified typmod.Otherwise planner optimizations might not happen.It appears we missed this point because the previous experiments weredone on type numeric: the parser undesirably generates a call on thenumeric() length-coercion function, but then numeric_support()optimizes that down to a RelabelType, so that everything seems fine.It misbehaves for types that have a non-optimized length coercionfunction, such as bpchar.Per report from John Naylor. Back-patch to all supported branches,as the previous patch eventually was. Unfortunately, that no longerincludes 9.6 ... we really shouldn't put this type of change into anearly-EOL branch.Discussion:https://postgr.es/m/CAFBsxsEfbFHEkouc+FSj+3K1sHipLPbEC67L0SAe-9-da8QtYg@mail.gmail.com
1 parentf04aa65 commite1fd61c

File tree

3 files changed

+61
-1
lines changed

3 files changed

+61
-1
lines changed

‎src/backend/parser/parse_coerce.c

Lines changed: 9 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -760,7 +760,15 @@ coerce_type_typmod(Node *node, Oid targetTypeId, int32 targetTypMod,
760760
if (hideInputCoercion)
761761
hide_coercion_node(node);
762762

763-
pathtype=find_typmod_coercion_function(targetTypeId,&funcId);
763+
/*
764+
* A negative typmod means that no actual coercion is needed, but we still
765+
* want a RelabelType to ensure that the expression exposes the intended
766+
* typmod.
767+
*/
768+
if (targetTypMod<0)
769+
pathtype=COERCION_PATH_NONE;
770+
else
771+
pathtype=find_typmod_coercion_function(targetTypeId,&funcId);
764772

765773
if (pathtype!=COERCION_PATH_NONE)
766774
{

‎src/test/regress/expected/expressions.out

Lines changed: 36 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -111,4 +111,40 @@ explain (verbose, costs off) select * from numeric_view;
111111
Output: numeric_tbl.f1, (numeric_tbl.f1)::numeric(16,4), (numeric_tbl.f1)::numeric, numeric_tbl.f2, (numeric_tbl.f2)::numeric(16,4), numeric_tbl.f2
112112
(2 rows)
113113

114+
-- bpchar, lacking planner support for its length coercion function,
115+
-- could behave differently
116+
create table bpchar_tbl (f1 character(16) unique, f2 bpchar);
117+
create view bpchar_view as
118+
select
119+
f1, f1::character(14) as f114, f1::bpchar as f1n,
120+
f2, f2::character(14) as f214, f2::bpchar as f2n
121+
from bpchar_tbl;
122+
\d+ bpchar_view
123+
View "public.bpchar_view"
124+
Column | Type | Collation | Nullable | Default | Storage | Description
125+
--------+---------------+-----------+----------+---------+----------+-------------
126+
f1 | character(16) | | | | extended |
127+
f114 | character(14) | | | | extended |
128+
f1n | bpchar | | | | extended |
129+
f2 | bpchar | | | | extended |
130+
f214 | character(14) | | | | extended |
131+
f2n | bpchar | | | | extended |
132+
View definition:
133+
SELECT bpchar_tbl.f1,
134+
bpchar_tbl.f1::character(14) AS f114,
135+
bpchar_tbl.f1::bpchar AS f1n,
136+
bpchar_tbl.f2,
137+
bpchar_tbl.f2::character(14) AS f214,
138+
bpchar_tbl.f2 AS f2n
139+
FROM bpchar_tbl;
140+
141+
explain (verbose, costs off) select * from bpchar_view
142+
where f1::bpchar = 'foo';
143+
QUERY PLAN
144+
------------------------------------------------------------------------------------------------------------------------------------------------
145+
Index Scan using bpchar_tbl_f1_key on public.bpchar_tbl
146+
Output: bpchar_tbl.f1, (bpchar_tbl.f1)::character(14), (bpchar_tbl.f1)::bpchar, bpchar_tbl.f2, (bpchar_tbl.f2)::character(14), bpchar_tbl.f2
147+
Index Cond: ((bpchar_tbl.f1)::bpchar = 'foo'::bpchar)
148+
(3 rows)
149+
114150
rollback;

‎src/test/regress/sql/expressions.sql

Lines changed: 16 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -53,4 +53,20 @@ create view numeric_view as
5353

5454
explain (verbose, costs off)select*from numeric_view;
5555

56+
-- bpchar, lacking planner support for its length coercion function,
57+
-- could behave differently
58+
59+
createtablebpchar_tbl (f1 character(16) unique, f2 bpchar);
60+
61+
createviewbpchar_viewas
62+
select
63+
f1, f1::character(14)as f114, f1::bpcharas f1n,
64+
f2, f2::character(14)as f214, f2::bpcharas f2n
65+
from bpchar_tbl;
66+
67+
\d+ bpchar_view
68+
69+
explain (verbose, costs off)select*from bpchar_view
70+
where f1::bpchar='foo';
71+
5672
rollback;

0 commit comments

Comments
 (0)
[8]ページ先頭
©2009-2025 Movatter.jp