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

Commit9c356f4

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 parentcf0cab8 commit9c356f4

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
@@ -766,7 +766,15 @@ coerce_type_typmod(Node *node, Oid targetTypeId, int32 targetTypMod,
766766
if (hideInputCoercion)
767767
hide_coercion_node(node);
768768

769-
pathtype=find_typmod_coercion_function(targetTypeId,&funcId);
769+
/*
770+
* A negative typmod means that no actual coercion is needed, but we still
771+
* want a RelabelType to ensure that the expression exposes the intended
772+
* typmod.
773+
*/
774+
if (targetTypMod<0)
775+
pathtype=COERCION_PATH_NONE;
776+
else
777+
pathtype=find_typmod_coercion_function(targetTypeId,&funcId);
770778

771779
if (pathtype!=COERCION_PATH_NONE)
772780
{

‎src/test/regress/expected/expressions.out

Lines changed: 36 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -194,6 +194,42 @@ explain (verbose, costs off) select * from numeric_view;
194194
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
195195
(2 rows)
196196

197+
-- bpchar, lacking planner support for its length coercion function,
198+
-- could behave differently
199+
create table bpchar_tbl (f1 character(16) unique, f2 bpchar);
200+
create view bpchar_view as
201+
select
202+
f1, f1::character(14) as f114, f1::bpchar as f1n,
203+
f2, f2::character(14) as f214, f2::bpchar as f2n
204+
from bpchar_tbl;
205+
\d+ bpchar_view
206+
View "public.bpchar_view"
207+
Column | Type | Collation | Nullable | Default | Storage | Description
208+
--------+---------------+-----------+----------+---------+----------+-------------
209+
f1 | character(16) | | | | extended |
210+
f114 | character(14) | | | | extended |
211+
f1n | bpchar | | | | extended |
212+
f2 | bpchar | | | | extended |
213+
f214 | character(14) | | | | extended |
214+
f2n | bpchar | | | | extended |
215+
View definition:
216+
SELECT bpchar_tbl.f1,
217+
bpchar_tbl.f1::character(14) AS f114,
218+
bpchar_tbl.f1::bpchar AS f1n,
219+
bpchar_tbl.f2,
220+
bpchar_tbl.f2::character(14) AS f214,
221+
bpchar_tbl.f2 AS f2n
222+
FROM bpchar_tbl;
223+
224+
explain (verbose, costs off) select * from bpchar_view
225+
where f1::bpchar = 'foo';
226+
QUERY PLAN
227+
------------------------------------------------------------------------------------------------------------------------------------------------
228+
Index Scan using bpchar_tbl_f1_key on public.bpchar_tbl
229+
Output: bpchar_tbl.f1, (bpchar_tbl.f1)::character(14), (bpchar_tbl.f1)::bpchar, bpchar_tbl.f2, (bpchar_tbl.f2)::character(14), bpchar_tbl.f2
230+
Index Cond: ((bpchar_tbl.f1)::bpchar = 'foo'::bpchar)
231+
(3 rows)
232+
197233
rollback;
198234
--
199235
-- Tests for ScalarArrayOpExpr with a hashfn

‎src/test/regress/sql/expressions.sql

Lines changed: 16 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -84,6 +84,22 @@ create view numeric_view as
8484

8585
explain (verbose, costs off)select*from numeric_view;
8686

87+
-- bpchar, lacking planner support for its length coercion function,
88+
-- could behave differently
89+
90+
createtablebpchar_tbl (f1 character(16) unique, f2 bpchar);
91+
92+
createviewbpchar_viewas
93+
select
94+
f1, f1::character(14)as f114, f1::bpcharas f1n,
95+
f2, f2::character(14)as f214, f2::bpcharas f2n
96+
from bpchar_tbl;
97+
98+
\d+ bpchar_view
99+
100+
explain (verbose, costs off)select*from bpchar_view
101+
where f1::bpchar='foo';
102+
87103
rollback;
88104

89105

0 commit comments

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