Make INSERT-from-multiple-VALUES-rows handle domain target columns.

Commit a3c7a993d fixed some cases involving target columns that are
arrays or composites by applying transformAssignedExpr to the VALUES
entries, and then stripping off any assignment ArrayRefs or
FieldStores that the transformation added.  But I forgot about domains
over arrays or composites :-(.  Such cases would either fail with
surprising complaints about mismatched datatypes, or insert unexpected
coercions that could lead to odd results.  To fix, extend the
stripping logic to get rid of CoerceToDomain if it's atop an ArrayRef
or FieldStore.

While poking at this, I realized that there's a poorly documented and
not-at-all-tested behavior nearby: we coerce each VALUES column to
the domain type separately, and rely on the rewriter to merge those
operations so that the domain constraints are checked only once.
If that merging did not happen, it's entirely possible that we'd get
unexpected domain constraint failures due to checking a
partially-updated container value.  There's no bug there, but while
we're here let's improve the commentary about it and add some test
cases that explicitly exercise that behavior.

Per bug #18393 from Pablo Kharo.  Back-patch to all supported
branches.

Discussion: https://postgr.es/m/18393-65fedb1a0de9260d@postgresql.org
This commit is contained in:
Tom Lane 2024-03-14 14:57:16 -04:00
parent d1162cfda8
commit b4a71cf65d
5 changed files with 227 additions and 11 deletions

View File

@ -1070,17 +1070,28 @@ transformInsertRow(ParseState *pstate, List *exprlist,
if (strip_indirection)
{
/*
* We need to remove top-level FieldStores and SubscriptingRefs,
* as well as any CoerceToDomain appearing above one of those ---
* but not a CoerceToDomain that isn't above one of those.
*/
while (expr)
{
if (IsA(expr, FieldStore))
Expr *subexpr = expr;
while (IsA(subexpr, CoerceToDomain))
{
FieldStore *fstore = (FieldStore *) expr;
subexpr = ((CoerceToDomain *) subexpr)->arg;
}
if (IsA(subexpr, FieldStore))
{
FieldStore *fstore = (FieldStore *) subexpr;
expr = (Expr *) linitial(fstore->newvals);
}
else if (IsA(expr, SubscriptingRef))
else if (IsA(subexpr, SubscriptingRef))
{
SubscriptingRef *sbsref = (SubscriptingRef *) expr;
SubscriptingRef *sbsref = (SubscriptingRef *) subexpr;
if (sbsref->refassgnexpr == NULL)
break;

View File

@ -820,7 +820,16 @@ transformAssignmentIndirection(ParseState *pstate,
fstore->fieldnums = list_make1_int(attnum);
fstore->resulttype = baseTypeId;
/* If target is a domain, apply constraints */
/*
* If target is a domain, apply constraints. Notice that this
* isn't totally right: the expression tree we build would check
* the domain's constraints on a composite value with only this
* one field populated or updated, possibly leading to an unwanted
* failure. The rewriter will merge together any subfield
* assignments to the same table column, resulting in the domain's
* constraints being checked only once after we've assigned to all
* the fields that the INSERT or UPDATE means to.
*/
if (baseTypeId != targetTypeId)
return coerce_to_domain((Node *) fstore,
baseTypeId, baseTypeMod,
@ -966,7 +975,12 @@ transformAssignmentSubscripts(ParseState *pstate,
result = (Node *) sbsref;
/* If target was a domain over container, need to coerce up to the domain */
/*
* If target was a domain over container, need to coerce up to the domain.
* As in transformAssignmentIndirection, this coercion is premature if the
* query assigns to multiple elements of the container; but we'll fix that
* during query rewrite.
*/
if (containerType != targetTypeId)
{
Oid resulttype = exprType(result);

View File

@ -1086,9 +1086,9 @@ process_matched_tle(TargetEntry *src_tle,
* resulting in each assignment containing a CoerceToDomain node over a
* FieldStore or SubscriptingRef. These should have matching target
* domains, so we strip them and reconstitute a single CoerceToDomain over
* the combined FieldStore/SubscriptingRef nodes. (Notice that this has the
* result that the domain's checks are applied only after we do all the
* field or element updates, not after each one. This is arguably desirable.)
* the combined FieldStore/SubscriptingRef nodes. (Notice that this has
* the result that the domain's checks are applied only after we do all
* the field or element updates, not after each one. This is desirable.)
*----------
*/
src_expr = (Node *) src_tle->expr;

View File

@ -180,7 +180,121 @@ Rules:
drop table inserttest2;
drop table inserttest;
drop type insert_test_type;
-- Make the same tests with domains over the array and composite fields
create domain insert_pos_ints as int[] check (value[1] > 0);
create domain insert_test_domain as insert_test_type
check ((value).if2[1] is not null);
create table inserttesta (f1 int, f2 insert_pos_ints);
create table inserttestb (f3 insert_test_domain, f4 insert_test_domain[]);
insert into inserttesta (f2[1], f2[2]) values (1,2);
insert into inserttesta (f2[1], f2[2]) values (3,4), (5,6);
insert into inserttesta (f2[1], f2[2]) select 7,8;
insert into inserttesta (f2[1], f2[2]) values (1,default); -- not supported
ERROR: cannot set an array element to DEFAULT
LINE 1: insert into inserttesta (f2[1], f2[2]) values (1,default);
^
insert into inserttesta (f2[1], f2[2]) values (0,2);
ERROR: value for domain insert_pos_ints violates check constraint "insert_pos_ints_check"
insert into inserttesta (f2[1], f2[2]) values (3,4), (0,6);
ERROR: value for domain insert_pos_ints violates check constraint "insert_pos_ints_check"
insert into inserttesta (f2[1], f2[2]) select 0,8;
ERROR: value for domain insert_pos_ints violates check constraint "insert_pos_ints_check"
insert into inserttestb (f3.if1, f3.if2) values (1,array['foo']);
insert into inserttestb (f3.if1, f3.if2) values (1,'{foo}'), (2,'{bar}');
insert into inserttestb (f3.if1, f3.if2) select 3, '{baz,quux}';
insert into inserttestb (f3.if1, f3.if2) values (1,default); -- not supported
ERROR: cannot set a subfield to DEFAULT
LINE 1: insert into inserttestb (f3.if1, f3.if2) values (1,default);
^
insert into inserttestb (f3.if1, f3.if2) values (1,array[null]);
ERROR: value for domain insert_test_domain violates check constraint "insert_test_domain_check"
insert into inserttestb (f3.if1, f3.if2) values (1,'{null}'), (2,'{bar}');
ERROR: value for domain insert_test_domain violates check constraint "insert_test_domain_check"
insert into inserttestb (f3.if1, f3.if2) select 3, '{null,quux}';
ERROR: value for domain insert_test_domain violates check constraint "insert_test_domain_check"
insert into inserttestb (f3.if2[1], f3.if2[2]) values ('foo', 'bar');
insert into inserttestb (f3.if2[1], f3.if2[2]) values ('foo', 'bar'), ('baz', 'quux');
insert into inserttestb (f3.if2[1], f3.if2[2]) select 'bear', 'beer';
insert into inserttestb (f3, f4[1].if2[1], f4[1].if2[2]) values (row(1,'{x}'), 'foo', 'bar');
insert into inserttestb (f3, f4[1].if2[1], f4[1].if2[2]) values (row(1,'{x}'), 'foo', 'bar'), (row(2,'{y}'), 'baz', 'quux');
insert into inserttestb (f3, f4[1].if2[1], f4[1].if2[2]) select row(1,'{x}')::insert_test_domain, 'bear', 'beer';
select * from inserttesta;
f1 | f2
----+-------
| {1,2}
| {3,4}
| {5,6}
| {7,8}
(4 rows)
select * from inserttestb;
f3 | f4
------------------+------------------------
(1,{foo}) |
(1,{foo}) |
(2,{bar}) |
(3,"{baz,quux}") |
(,"{foo,bar}") |
(,"{foo,bar}") |
(,"{baz,quux}") |
(,"{bear,beer}") |
(1,{x}) | {"(,\"{foo,bar}\")"}
(1,{x}) | {"(,\"{foo,bar}\")"}
(2,{y}) | {"(,\"{baz,quux}\")"}
(1,{x}) | {"(,\"{bear,beer}\")"}
(12 rows)
-- also check reverse-listing
create table inserttest2 (f1 bigint, f2 text);
create rule irule1 as on insert to inserttest2 do also
insert into inserttestb (f3.if2[1], f3.if2[2])
values (new.f1,new.f2);
create rule irule2 as on insert to inserttest2 do also
insert into inserttestb (f4[1].if1, f4[1].if2[2])
values (1,'fool'),(new.f1,new.f2);
create rule irule3 as on insert to inserttest2 do also
insert into inserttestb (f4[1].if1, f4[1].if2[2])
select new.f1, new.f2;
\d+ inserttest2
Table "public.inserttest2"
Column | Type | Collation | Nullable | Default | Storage | Stats target | Description
--------+--------+-----------+----------+---------+----------+--------------+-------------
f1 | bigint | | | | plain | |
f2 | text | | | | extended | |
Rules:
irule1 AS
ON INSERT TO inserttest2 DO INSERT INTO inserttestb (f3.if2[1], f3.if2[2])
VALUES (new.f1, new.f2)
irule2 AS
ON INSERT TO inserttest2 DO INSERT INTO inserttestb (f4[1].if1, f4[1].if2[2]) VALUES (1,'fool'::text), (new.f1,new.f2)
irule3 AS
ON INSERT TO inserttest2 DO INSERT INTO inserttestb (f4[1].if1, f4[1].if2[2]) SELECT new.f1,
new.f2
drop table inserttest2;
drop table inserttesta;
drop table inserttestb;
drop domain insert_pos_ints;
drop domain insert_test_domain;
-- Verify that multiple inserts to subfields of a domain-over-container
-- check the domain constraints only on the finished value
create domain insert_nnarray as int[]
check (value[1] is not null and value[2] is not null);
create domain insert_test_domain as insert_test_type
check ((value).if1 is not null and (value).if2 is not null);
create table inserttesta (f1 insert_nnarray);
insert into inserttesta (f1[1]) values (1); -- fail
ERROR: value for domain insert_nnarray violates check constraint "insert_nnarray_check"
insert into inserttesta (f1[1], f1[2]) values (1, 2);
create table inserttestb (f1 insert_test_domain);
insert into inserttestb (f1.if1) values (1); -- fail
ERROR: value for domain insert_test_domain violates check constraint "insert_test_domain_check"
insert into inserttestb (f1.if1, f1.if2) values (1, '{foo}');
drop table inserttesta;
drop table inserttestb;
drop domain insert_nnarray;
drop type insert_test_type cascade;
NOTICE: drop cascades to type insert_test_domain
-- direct partition inserts should check partition bound constraint
create table range_parted (
a text,

View File

@ -105,7 +105,84 @@ create rule irule3 as on insert to inserttest2 do also
drop table inserttest2;
drop table inserttest;
drop type insert_test_type;
-- Make the same tests with domains over the array and composite fields
create domain insert_pos_ints as int[] check (value[1] > 0);
create domain insert_test_domain as insert_test_type
check ((value).if2[1] is not null);
create table inserttesta (f1 int, f2 insert_pos_ints);
create table inserttestb (f3 insert_test_domain, f4 insert_test_domain[]);
insert into inserttesta (f2[1], f2[2]) values (1,2);
insert into inserttesta (f2[1], f2[2]) values (3,4), (5,6);
insert into inserttesta (f2[1], f2[2]) select 7,8;
insert into inserttesta (f2[1], f2[2]) values (1,default); -- not supported
insert into inserttesta (f2[1], f2[2]) values (0,2);
insert into inserttesta (f2[1], f2[2]) values (3,4), (0,6);
insert into inserttesta (f2[1], f2[2]) select 0,8;
insert into inserttestb (f3.if1, f3.if2) values (1,array['foo']);
insert into inserttestb (f3.if1, f3.if2) values (1,'{foo}'), (2,'{bar}');
insert into inserttestb (f3.if1, f3.if2) select 3, '{baz,quux}';
insert into inserttestb (f3.if1, f3.if2) values (1,default); -- not supported
insert into inserttestb (f3.if1, f3.if2) values (1,array[null]);
insert into inserttestb (f3.if1, f3.if2) values (1,'{null}'), (2,'{bar}');
insert into inserttestb (f3.if1, f3.if2) select 3, '{null,quux}';
insert into inserttestb (f3.if2[1], f3.if2[2]) values ('foo', 'bar');
insert into inserttestb (f3.if2[1], f3.if2[2]) values ('foo', 'bar'), ('baz', 'quux');
insert into inserttestb (f3.if2[1], f3.if2[2]) select 'bear', 'beer';
insert into inserttestb (f3, f4[1].if2[1], f4[1].if2[2]) values (row(1,'{x}'), 'foo', 'bar');
insert into inserttestb (f3, f4[1].if2[1], f4[1].if2[2]) values (row(1,'{x}'), 'foo', 'bar'), (row(2,'{y}'), 'baz', 'quux');
insert into inserttestb (f3, f4[1].if2[1], f4[1].if2[2]) select row(1,'{x}')::insert_test_domain, 'bear', 'beer';
select * from inserttesta;
select * from inserttestb;
-- also check reverse-listing
create table inserttest2 (f1 bigint, f2 text);
create rule irule1 as on insert to inserttest2 do also
insert into inserttestb (f3.if2[1], f3.if2[2])
values (new.f1,new.f2);
create rule irule2 as on insert to inserttest2 do also
insert into inserttestb (f4[1].if1, f4[1].if2[2])
values (1,'fool'),(new.f1,new.f2);
create rule irule3 as on insert to inserttest2 do also
insert into inserttestb (f4[1].if1, f4[1].if2[2])
select new.f1, new.f2;
\d+ inserttest2
drop table inserttest2;
drop table inserttesta;
drop table inserttestb;
drop domain insert_pos_ints;
drop domain insert_test_domain;
-- Verify that multiple inserts to subfields of a domain-over-container
-- check the domain constraints only on the finished value
create domain insert_nnarray as int[]
check (value[1] is not null and value[2] is not null);
create domain insert_test_domain as insert_test_type
check ((value).if1 is not null and (value).if2 is not null);
create table inserttesta (f1 insert_nnarray);
insert into inserttesta (f1[1]) values (1); -- fail
insert into inserttesta (f1[1], f1[2]) values (1, 2);
create table inserttestb (f1 insert_test_domain);
insert into inserttestb (f1.if1) values (1); -- fail
insert into inserttestb (f1.if1, f1.if2) values (1, '{foo}');
drop table inserttesta;
drop table inserttestb;
drop domain insert_nnarray;
drop type insert_test_type cascade;
-- direct partition inserts should check partition bound constraint
create table range_parted (