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-rw-r--r--src/backend/optimizer/plan/planner.c2
-rw-r--r--src/backend/optimizer/plan/subselect.c2
-rw-r--r--src/backend/optimizer/prep/prepqual.c83
-rw-r--r--src/backend/optimizer/util/plancat.c2
-rw-r--r--src/backend/utils/cache/relcache.c5
-rw-r--r--src/include/optimizer/prep.h1
-rw-r--r--src/test/regress/expected/inherit.out24
-rw-r--r--src/test/regress/sql/inherit.sql12
8 files changed, 105 insertions, 26 deletions
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index 716af49d465..615f1cbc01d 100644
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -742,7 +742,7 @@ preprocess_expression(PlannerInfo *root, Node *expr, int kind)
*/
if (kind == EXPRKIND_QUAL)
{
- expr = (Node *) canonicalize_qual((Expr *) expr);
+ expr = (Node *) canonicalize_qual_ext((Expr *) expr, false);
#ifdef OPTIMIZER_DEBUG
printf("After canonicalize_qual()\n");
diff --git a/src/backend/optimizer/plan/subselect.c b/src/backend/optimizer/plan/subselect.c
index e400ea983cc..9c7172c7751 100644
--- a/src/backend/optimizer/plan/subselect.c
+++ b/src/backend/optimizer/plan/subselect.c
@@ -1696,7 +1696,7 @@ convert_EXISTS_to_ANY(PlannerInfo *root, Query *subselect,
* subroot.
*/
whereClause = eval_const_expressions(root, whereClause);
- whereClause = (Node *) canonicalize_qual((Expr *) whereClause);
+ whereClause = (Node *) canonicalize_qual_ext((Expr *) whereClause, false);
whereClause = (Node *) make_ands_implicit((Expr *) whereClause);
/*
diff --git a/src/backend/optimizer/prep/prepqual.c b/src/backend/optimizer/prep/prepqual.c
index 1176e819dd0..7e8b8e7abca 100644
--- a/src/backend/optimizer/prep/prepqual.c
+++ b/src/backend/optimizer/prep/prepqual.c
@@ -39,7 +39,7 @@
static List *pull_ands(List *andlist);
static List *pull_ors(List *orlist);
-static Expr *find_duplicate_ors(Expr *qual);
+static Expr *find_duplicate_ors(Expr *qual, bool is_check);
static Expr *process_duplicate_ors(List *orlist);
@@ -269,6 +269,24 @@ negate_clause(Node *node)
* canonicalize_qual
* Convert a qualification expression to the most useful form.
*
+ * Backwards-compatibility wrapper for use by external code that hasn't
+ * been updated.
+ */
+Expr *
+canonicalize_qual(Expr *qual)
+{
+ return canonicalize_qual_ext(qual, false);
+}
+
+/*
+ * canonicalize_qual_ext
+ * Convert a qualification expression to the most useful form.
+ *
+ * This is primarily intended to be used on top-level WHERE (or JOIN/ON)
+ * clauses. It can also be used on top-level CHECK constraints, for which
+ * pass is_check = true. DO NOT call it on any expression that is not known
+ * to be one or the other, as it might apply inappropriate simplifications.
+ *
* The name of this routine is a holdover from a time when it would try to
* force the expression into canonical AND-of-ORs or OR-of-ANDs form.
* Eventually, we recognized that that had more theoretical purity than
@@ -283,7 +301,7 @@ negate_clause(Node *node)
* Returns the modified qualification.
*/
Expr *
-canonicalize_qual(Expr *qual)
+canonicalize_qual_ext(Expr *qual, bool is_check)
{
Expr *newqual;
@@ -296,7 +314,7 @@ canonicalize_qual(Expr *qual)
* within the top-level AND/OR structure; there's no point in looking
* deeper. Also remove any NULL constants in the top-level structure.
*/
- newqual = find_duplicate_ors(qual);
+ newqual = find_duplicate_ors(qual, is_check);
return newqual;
}
@@ -395,16 +413,17 @@ pull_ors(List *orlist)
* Only the top-level AND/OR structure is searched.
*
* While at it, we remove any NULL constants within the top-level AND/OR
- * structure, eg "x OR NULL::boolean" is reduced to "x". In general that
- * would change the result, so eval_const_expressions can't do it; but at
- * top level of WHERE, we don't need to distinguish between FALSE and NULL
- * results, so it's valid to treat NULL::boolean the same as FALSE and then
- * simplify AND/OR accordingly.
+ * structure, eg in a WHERE clause, "x OR NULL::boolean" is reduced to "x".
+ * In general that would change the result, so eval_const_expressions can't
+ * do it; but at top level of WHERE, we don't need to distinguish between
+ * FALSE and NULL results, so it's valid to treat NULL::boolean the same
+ * as FALSE and then simplify AND/OR accordingly. Conversely, in a top-level
+ * CHECK constraint, we may treat a NULL the same as TRUE.
*
* Returns the modified qualification. AND/OR flatness is preserved.
*/
static Expr *
-find_duplicate_ors(Expr *qual)
+find_duplicate_ors(Expr *qual, bool is_check)
{
if (or_clause((Node *) qual))
{
@@ -416,18 +435,29 @@ find_duplicate_ors(Expr *qual)
{
Expr *arg = (Expr *) lfirst(temp);
- arg = find_duplicate_ors(arg);
+ arg = find_duplicate_ors(arg, is_check);
/* Get rid of any constant inputs */
if (arg && IsA(arg, Const))
{
Const *carg = (Const *) arg;
- /* Drop constant FALSE or NULL */
- if (carg->constisnull || !DatumGetBool(carg->constvalue))
- continue;
- /* constant TRUE, so OR reduces to TRUE */
- return arg;
+ if (is_check)
+ {
+ /* Within OR in CHECK, drop constant FALSE */
+ if (!carg->constisnull && !DatumGetBool(carg->constvalue))
+ continue;
+ /* Constant TRUE or NULL, so OR reduces to TRUE */
+ return (Expr *) makeBoolConst(true, false);
+ }
+ else
+ {
+ /* Within OR in WHERE, drop constant FALSE or NULL */
+ if (carg->constisnull || !DatumGetBool(carg->constvalue))
+ continue;
+ /* Constant TRUE, so OR reduces to TRUE */
+ return arg;
+ }
}
orlist = lappend(orlist, arg);
@@ -449,18 +479,29 @@ find_duplicate_ors(Expr *qual)
{
Expr *arg = (Expr *) lfirst(temp);
- arg = find_duplicate_ors(arg);
+ arg = find_duplicate_ors(arg, is_check);
/* Get rid of any constant inputs */
if (arg && IsA(arg, Const))
{
Const *carg = (Const *) arg;
- /* Drop constant TRUE */
- if (!carg->constisnull && DatumGetBool(carg->constvalue))
- continue;
- /* constant FALSE or NULL, so AND reduces to FALSE */
- return (Expr *) makeBoolConst(false, false);
+ if (is_check)
+ {
+ /* Within AND in CHECK, drop constant TRUE or NULL */
+ if (carg->constisnull || DatumGetBool(carg->constvalue))
+ continue;
+ /* Constant FALSE, so AND reduces to FALSE */
+ return arg;
+ }
+ else
+ {
+ /* Within AND in WHERE, drop constant TRUE */
+ if (!carg->constisnull && DatumGetBool(carg->constvalue))
+ continue;
+ /* Constant FALSE or NULL, so AND reduces to FALSE */
+ return (Expr *) makeBoolConst(false, false);
+ }
}
andlist = lappend(andlist, arg);
diff --git a/src/backend/optimizer/util/plancat.c b/src/backend/optimizer/util/plancat.c
index f037f90d985..ac57d0f2b89 100644
--- a/src/backend/optimizer/util/plancat.c
+++ b/src/backend/optimizer/util/plancat.c
@@ -1056,7 +1056,7 @@ get_relation_constraints(PlannerInfo *root,
*/
cexpr = eval_const_expressions(root, cexpr);
- cexpr = (Node *) canonicalize_qual((Expr *) cexpr);
+ cexpr = (Node *) canonicalize_qual_ext((Expr *) cexpr, true);
/* Fix Vars to have the desired varno */
if (varno != 1)
diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index 4ebe103c1ad..afaf8794f00 100644
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -4091,7 +4091,8 @@ RelationGetIndexExpressions(Relation relation)
* Run the expressions through eval_const_expressions. This is not just an
* optimization, but is necessary, because the planner will be comparing
* them to similarly-processed qual clauses, and may fail to detect valid
- * matches without this. We don't bother with canonicalize_qual, however.
+ * matches without this. We must not use canonicalize_qual, however,
+ * since these aren't qual expressions.
*/
result = (List *) eval_const_expressions(NULL, (Node *) result);
@@ -4159,7 +4160,7 @@ RelationGetIndexPredicate(Relation relation)
*/
result = (List *) eval_const_expressions(NULL, (Node *) result);
- result = (List *) canonicalize_qual((Expr *) result);
+ result = (List *) canonicalize_qual_ext((Expr *) result, false);
/* Also convert to implicit-AND format */
result = make_ands_implicit((Expr *) result);
diff --git a/src/include/optimizer/prep.h b/src/include/optimizer/prep.h
index 46fadff5360..f87bcb6e855 100644
--- a/src/include/optimizer/prep.h
+++ b/src/include/optimizer/prep.h
@@ -34,6 +34,7 @@ extern Relids get_relids_for_join(PlannerInfo *root, int joinrelid);
*/
extern Node *negate_clause(Node *node);
extern Expr *canonicalize_qual(Expr *qual);
+extern Expr *canonicalize_qual_ext(Expr *qual, bool is_check);
/*
* prototypes for prepsecurity.c
diff --git a/src/test/regress/expected/inherit.out b/src/test/regress/expected/inherit.out
index 4f465a5f1ef..50d3403011a 100644
--- a/src/test/regress/expected/inherit.out
+++ b/src/test/regress/expected/inherit.out
@@ -1591,3 +1591,27 @@ FROM generate_series(1, 3) g(i);
reset enable_seqscan;
reset enable_indexscan;
reset enable_bitmapscan;
+--
+-- Check handling of a constant-null CHECK constraint
+--
+create table cnullparent (f1 int);
+create table cnullchild (check (f1 = 1 or f1 = null)) inherits(cnullparent);
+insert into cnullchild values(1);
+insert into cnullchild values(2);
+insert into cnullchild values(null);
+select * from cnullparent;
+ f1
+----
+ 1
+ 2
+
+(3 rows)
+
+select * from cnullparent where f1 = 2;
+ f1
+----
+ 2
+(1 row)
+
+drop table cnullparent cascade;
+NOTICE: drop cascades to table cnullchild
diff --git a/src/test/regress/sql/inherit.sql b/src/test/regress/sql/inherit.sql
index 0e390cda3e4..385359b7611 100644
--- a/src/test/regress/sql/inherit.sql
+++ b/src/test/regress/sql/inherit.sql
@@ -562,3 +562,15 @@ FROM generate_series(1, 3) g(i);
reset enable_seqscan;
reset enable_indexscan;
reset enable_bitmapscan;
+
+--
+-- Check handling of a constant-null CHECK constraint
+--
+create table cnullparent (f1 int);
+create table cnullchild (check (f1 = 1 or f1 = null)) inherits(cnullparent);
+insert into cnullchild values(1);
+insert into cnullchild values(2);
+insert into cnullchild values(null);
+select * from cnullparent;
+select * from cnullparent where f1 = 2;
+drop table cnullparent cascade;
generated by cgit v1.2.3 (git 2.25.1) at 2025-06-06 09:06:44 +0000