Record range constructor functions in pg_range

When a range type is created, several construction functions are also
created, two for the range type and three for the multirange type.
These have an internal dependency, so they "belong" to the range type.
But there was no way to identify those functions when given a range
type.  An upcoming patch needs access to the two- or possibly the
three-argument range constructor function for a given range type.  The
only way to do that would be with fragile workarounds like matching
names and argument types.  The correct way to do that kind of thing is
to record to the links in the system catalogs.  This is what this
patch does, it records the OIDs of these five constructor functions in
the pg_range catalog.  (Currently, there is no code that makes use of
this.)

Reviewed-by: Paul A Jungwirth <pj@illuminatedcomputing.com>
Reviewed-by: Kirill Reshke <reshkekirill@gmail.com>
Discussion: https://www.postgresql.org/message-id/7d63ddfa-c735-4dfe-8c7a-4f1e2a621058%40eisentraut.org

doc/src/sgml/catalogs.sgml

@@ -6676,6 +6676,60 @@ SCRAM-SHA-256$<replaceable>&lt;iteration count&gt;</replaceable>:<replaceable>&l
       </para></entry>
      </row>
 
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>rngconstruct2</structfield> <type>regproc</type>
+       (references <link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.<structfield>oid</structfield>)
+      </para>
+      <para>
+       OID of the 2-argument range constructor function (lower and upper)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>rngconstruct3</structfield> <type>regproc</type>
+       (references <link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.<structfield>oid</structfield>)
+      </para>
+      <para>
+       OID of the 3-argument range constructor function (lower, upper, and
+       flags)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>rngmltconstruct0</structfield> <type>regproc</type>
+       (references <link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.<structfield>oid</structfield>)
+      </para>
+      <para>
+       OID of the 0-argument multirange constructor function (constructs empty
+       range)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>rngmltconstruct1</structfield> <type>regproc</type>
+       (references <link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.<structfield>oid</structfield>)
+      </para>
+      <para>
+       OID of the 1-argument multirange constructor function (constructs
+       multirange from single range, also used as cast function)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>rngmltconstruct2</structfield> <type>regproc</type>
+       (references <link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.<structfield>oid</structfield>)
+      </para>
+      <para>
+       OID of the 2-argument multirange constructor function (constructs
+       multirange from array of ranges)
+      </para></entry>
+     </row>
+
      <row>
       <entry role="catalog_table_entry"><para role="column_definition">
        <structfield>rngcanonical</structfield> <type>regproc</type>

src/backend/catalog/pg_range.c

@@ -35,7 +35,9 @@
 void
 RangeCreate(Oid rangeTypeOid, Oid rangeSubType, Oid rangeCollation,
 			Oid rangeSubOpclass, RegProcedure rangeCanonical,
-			RegProcedure rangeSubDiff, Oid multirangeTypeOid)
+			RegProcedure rangeSubDiff, Oid multirangeTypeOid,
+			RegProcedure rangeConstruct2, RegProcedure rangeConstruct3,
+			RegProcedure mltrngConstruct0, RegProcedure mltrngConstruct1, RegProcedure mltrngConstruct2)
 {
 	Relation	pg_range;
 	Datum		values[Natts_pg_range];
@@ -57,6 +59,11 @@ RangeCreate(Oid rangeTypeOid, Oid rangeSubType, Oid rangeCollation,
 	values[Anum_pg_range_rngcanonical - 1] = ObjectIdGetDatum(rangeCanonical);
 	values[Anum_pg_range_rngsubdiff - 1] = ObjectIdGetDatum(rangeSubDiff);
 	values[Anum_pg_range_rngmultitypid - 1] = ObjectIdGetDatum(multirangeTypeOid);
+	values[Anum_pg_range_rngconstruct2 - 1] = ObjectIdGetDatum(rangeConstruct2);
+	values[Anum_pg_range_rngconstruct3 - 1] = ObjectIdGetDatum(rangeConstruct3);
+	values[Anum_pg_range_rngmltconstruct0 - 1] = ObjectIdGetDatum(mltrngConstruct0);
+	values[Anum_pg_range_rngmltconstruct1 - 1] = ObjectIdGetDatum(mltrngConstruct1);
+	values[Anum_pg_range_rngmltconstruct2 - 1] = ObjectIdGetDatum(mltrngConstruct2);
 
 	tup = heap_form_tuple(RelationGetDescr(pg_range), values, nulls);
 

src/backend/commands/typecmds.c

@@ -111,10 +111,12 @@ Oid			binary_upgrade_next_mrng_pg_type_oid = InvalidOid;
 Oid			binary_upgrade_next_mrng_array_pg_type_oid = InvalidOid;
 
 static void makeRangeConstructors(const char *name, Oid namespace,
-								  Oid rangeOid, Oid subtype);
+								  Oid rangeOid, Oid subtype,
+								  Oid *rangeConstruct2_p, Oid *rangeConstruct3_p);
 static void makeMultirangeConstructors(const char *name, Oid namespace,
 									   Oid multirangeOid, Oid rangeOid,
-									   Oid rangeArrayOid, Oid *castFuncOid);
+									   Oid rangeArrayOid,
+									   Oid *mltrngConstruct0_p, Oid *mltrngConstruct1_p, Oid *mltrngConstruct2_p);
 static Oid	findTypeInputFunction(List *procname, Oid typeOid);
 static Oid	findTypeOutputFunction(List *procname, Oid typeOid);
 static Oid	findTypeReceiveFunction(List *procname, Oid typeOid);
@@ -1406,6 +1408,11 @@ DefineRange(ParseState *pstate, CreateRangeStmt *stmt)
 	ListCell   *lc;
 	ObjectAddress address;
 	ObjectAddress mltrngaddress PG_USED_FOR_ASSERTS_ONLY;
+	Oid			rangeConstruct2Oid = InvalidOid;
+	Oid			rangeConstruct3Oid = InvalidOid;
+	Oid			mltrngConstruct0Oid = InvalidOid;
+	Oid			mltrngConstruct1Oid = InvalidOid;
+	Oid			mltrngConstruct2Oid = InvalidOid;
 	Oid			castFuncOid;
 
 	/* Convert list of names to a name and namespace */
@@ -1661,10 +1668,6 @@ DefineRange(ParseState *pstate, CreateRangeStmt *stmt)
 				   InvalidOid); /* type's collation (ranges never have one) */
 	Assert(multirangeOid == mltrngaddress.objectId);
 
-	/* Create the entry in pg_range */
-	RangeCreate(typoid, rangeSubtype, rangeCollation, rangeSubOpclass,
-				rangeCanonical, rangeSubtypeDiff, multirangeOid);
-
 	/*
 	 * Create the array type that goes with it.
 	 */
@@ -1746,10 +1749,18 @@ DefineRange(ParseState *pstate, CreateRangeStmt *stmt)
 	CommandCounterIncrement();
 
 	/* And create the constructor functions for this range type */
-	makeRangeConstructors(typeName, typeNamespace, typoid, rangeSubtype);
+	makeRangeConstructors(typeName, typeNamespace, typoid, rangeSubtype,
+						  &rangeConstruct2Oid, &rangeConstruct3Oid);
 	makeMultirangeConstructors(multirangeTypeName, typeNamespace,
 							   multirangeOid, typoid, rangeArrayOid,
-							   &castFuncOid);
+							   &mltrngConstruct0Oid, &mltrngConstruct1Oid, &mltrngConstruct2Oid);
+	castFuncOid = mltrngConstruct1Oid;
+
+	/* Create the entry in pg_range */
+	RangeCreate(typoid, rangeSubtype, rangeCollation, rangeSubOpclass,
+				rangeCanonical, rangeSubtypeDiff, multirangeOid,
+				rangeConstruct2Oid, rangeConstruct3Oid,
+				mltrngConstruct0Oid, mltrngConstruct1Oid, mltrngConstruct2Oid);
 
 	/* Create cast from the range type to its multirange type */
 	CastCreate(typoid, multirangeOid, castFuncOid, InvalidOid, InvalidOid,
@@ -1769,10 +1780,14 @@ DefineRange(ParseState *pstate, CreateRangeStmt *stmt)
  *
  * We actually define 2 functions, with 2 through 3 arguments.  This is just
  * to offer more convenience for the user.
+ *
+ * The OIDs of the created functions are returned through the pointer
+ * arguments.
  */
 static void
 makeRangeConstructors(const char *name, Oid namespace,
-					  Oid rangeOid, Oid subtype)
+					  Oid rangeOid, Oid subtype,
+					  Oid *rangeConstruct2_p, Oid *rangeConstruct3_p)
 {
 	static const char *const prosrc[2] = {"range_constructor2",
 	"range_constructor3"};
@@ -1833,6 +1848,11 @@ makeRangeConstructors(const char *name, Oid namespace,
 		 * pg_dump depends on this choice to avoid dumping the constructors.
 		 */
 		recordDependencyOn(&myself, &referenced, DEPENDENCY_INTERNAL);
+
+		if (pronargs[i] == 2)
+			*rangeConstruct2_p = myself.objectId;
+		else if (pronargs[i] == 3)
+			*rangeConstruct3_p = myself.objectId;
 	}
 }
 
@@ -1842,13 +1862,13 @@ makeRangeConstructors(const char *name, Oid namespace,
  * If we had an anyrangearray polymorphic type we could use it here,
  * but since each type has its own constructor name there's no need.
  *
- * Sets castFuncOid to the oid of the new constructor that can be used
- * to cast from a range to a multirange.
+ * The OIDs of the created functions are returned through the pointer
+ * arguments.
  */
 static void
 makeMultirangeConstructors(const char *name, Oid namespace,
 						   Oid multirangeOid, Oid rangeOid, Oid rangeArrayOid,
-						   Oid *castFuncOid)
+						   Oid *mltrngConstruct0_p, Oid *mltrngConstruct1_p, Oid *mltrngConstruct2_p)
 {
 	ObjectAddress myself,
 				referenced;
@@ -1899,6 +1919,7 @@ makeMultirangeConstructors(const char *name, Oid namespace,
 	 * depends on this choice to avoid dumping the constructors.
 	 */
 	recordDependencyOn(&myself, &referenced, DEPENDENCY_INTERNAL);
+	*mltrngConstruct0_p = myself.objectId;
 	pfree(argtypes);
 
 	/*
@@ -1939,8 +1960,8 @@ makeMultirangeConstructors(const char *name, Oid namespace,
 							 0.0);	/* prorows */
 	/* ditto */
 	recordDependencyOn(&myself, &referenced, DEPENDENCY_INTERNAL);
+	*mltrngConstruct1_p = myself.objectId;
 	pfree(argtypes);
-	*castFuncOid = myself.objectId;
 
 	/* n-arg constructor - vararg */
 	argtypes = buildoidvector(&rangeArrayOid, 1);
@@ -1978,6 +1999,7 @@ makeMultirangeConstructors(const char *name, Oid namespace,
 							 0.0);	/* prorows */
 	/* ditto */
 	recordDependencyOn(&myself, &referenced, DEPENDENCY_INTERNAL);
+	*mltrngConstruct2_p = myself.objectId;
 	pfree(argtypes);
 	pfree(allParameterTypes);
 	pfree(parameterModes);

src/include/catalog/catversion.h

@@ -57,6 +57,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	202601161
+#define CATALOG_VERSION_NO	202601221
 
 #endif

src/include/catalog/pg_range.dat

@@ -14,21 +14,33 @@
 
 { rngtypid => 'int4range', rngsubtype => 'int4',
   rngmultitypid => 'int4multirange', rngsubopc => 'btree/int4_ops',
+  rngconstruct2 => 'int4range(int4,int4)', rngconstruct3 => 'int4range(int4,int4,text)',
+  rngmltconstruct0 => 'int4multirange()', rngmltconstruct1 => 'int4multirange(int4range)', rngmltconstruct2 => 'int4multirange(_int4range)',
   rngcanonical => 'int4range_canonical', rngsubdiff => 'int4range_subdiff' },
 { rngtypid => 'numrange', rngsubtype => 'numeric',
   rngmultitypid => 'nummultirange', rngsubopc => 'btree/numeric_ops',
+  rngconstruct2 => 'numrange(numeric,numeric)', rngconstruct3 => 'numrange(numeric,numeric,text)',
+  rngmltconstruct0 => 'nummultirange()', rngmltconstruct1 => 'nummultirange(numrange)', rngmltconstruct2 => 'nummultirange(_numrange)',
   rngcanonical => '-', rngsubdiff => 'numrange_subdiff' },
 { rngtypid => 'tsrange', rngsubtype => 'timestamp',
   rngmultitypid => 'tsmultirange', rngsubopc => 'btree/timestamp_ops',
+  rngconstruct2 => 'tsrange(timestamp,timestamp)', rngconstruct3 => 'tsrange(timestamp,timestamp,text)',
+  rngmltconstruct0 => 'tsmultirange()', rngmltconstruct1 => 'tsmultirange(tsrange)', rngmltconstruct2 => 'tsmultirange(_tsrange)',
   rngcanonical => '-', rngsubdiff => 'tsrange_subdiff' },
 { rngtypid => 'tstzrange', rngsubtype => 'timestamptz',
   rngmultitypid => 'tstzmultirange', rngsubopc => 'btree/timestamptz_ops',
+  rngconstruct2 => 'tstzrange(timestamptz,timestamptz)', rngconstruct3 => 'tstzrange(timestamptz,timestamptz,text)',
+  rngmltconstruct0 => 'tstzmultirange()', rngmltconstruct1 => 'tstzmultirange(tstzrange)', rngmltconstruct2 => 'tstzmultirange(_tstzrange)',
   rngcanonical => '-', rngsubdiff => 'tstzrange_subdiff' },
 { rngtypid => 'daterange', rngsubtype => 'date',
   rngmultitypid => 'datemultirange', rngsubopc => 'btree/date_ops',
+  rngconstruct2 => 'daterange(date,date)', rngconstruct3 => 'daterange(date,date,text)',
+  rngmltconstruct0 => 'datemultirange()', rngmltconstruct1 => 'datemultirange(daterange)', rngmltconstruct2 => 'datemultirange(_daterange)',
   rngcanonical => 'daterange_canonical', rngsubdiff => 'daterange_subdiff' },
 { rngtypid => 'int8range', rngsubtype => 'int8',
   rngmultitypid => 'int8multirange', rngsubopc => 'btree/int8_ops',
+  rngconstruct2 => 'int8range(int8,int8)', rngconstruct3 => 'int8range(int8,int8,text)',
+  rngmltconstruct0 => 'int8multirange()', rngmltconstruct1 => 'int8multirange(int8range)', rngmltconstruct2 => 'int8multirange(_int8range)',
   rngcanonical => 'int8range_canonical', rngsubdiff => 'int8range_subdiff' },
 
 ]

src/include/catalog/pg_range.h

@@ -43,6 +43,15 @@ CATALOG(pg_range,3541,RangeRelationId)
 	/* subtype's btree opclass */
 	Oid			rngsubopc BKI_LOOKUP(pg_opclass);
 
+	/* range constructor functions */
+	regproc		rngconstruct2 BKI_LOOKUP(pg_proc);
+	regproc		rngconstruct3 BKI_LOOKUP(pg_proc);
+
+	/* multirange constructor functions */
+	regproc		rngmltconstruct0 BKI_LOOKUP(pg_proc);
+	regproc		rngmltconstruct1 BKI_LOOKUP(pg_proc);
+	regproc		rngmltconstruct2 BKI_LOOKUP(pg_proc);
+
 	/* canonicalize range, or 0 */
 	regproc		rngcanonical BKI_LOOKUP_OPT(pg_proc);
 
@@ -69,7 +78,9 @@ MAKE_SYSCACHE(RANGEMULTIRANGE, pg_range_rngmultitypid_index, 4);
 
 extern void RangeCreate(Oid rangeTypeOid, Oid rangeSubType, Oid rangeCollation,
 						Oid rangeSubOpclass, RegProcedure rangeCanonical,
-						RegProcedure rangeSubDiff, Oid multirangeTypeOid);
+						RegProcedure rangeSubDiff, Oid multirangeTypeOid,
+						RegProcedure rangeConstruct2, RegProcedure rangeConstruct3,
+						RegProcedure mltrngConstruct0, RegProcedure mltrngConstruct1, RegProcedure mltrngConstruct2);
 extern void RangeDelete(Oid rangeTypeOid);
 
 #endif							/* PG_RANGE_H */

src/test/regress/expected/oidjoins.out

@@ -249,6 +249,11 @@ NOTICE:  checking pg_range {rngsubtype} => pg_type {oid}
 NOTICE:  checking pg_range {rngmultitypid} => pg_type {oid}
 NOTICE:  checking pg_range {rngcollation} => pg_collation {oid}
 NOTICE:  checking pg_range {rngsubopc} => pg_opclass {oid}
+NOTICE:  checking pg_range {rngconstruct2} => pg_proc {oid}
+NOTICE:  checking pg_range {rngconstruct3} => pg_proc {oid}
+NOTICE:  checking pg_range {rngmltconstruct0} => pg_proc {oid}
+NOTICE:  checking pg_range {rngmltconstruct1} => pg_proc {oid}
+NOTICE:  checking pg_range {rngmltconstruct2} => pg_proc {oid}
 NOTICE:  checking pg_range {rngcanonical} => pg_proc {oid}
 NOTICE:  checking pg_range {rngsubdiff} => pg_proc {oid}
 NOTICE:  checking pg_transform {trftype} => pg_type {oid}

src/test/regress/expected/type_sanity.out

@@ -610,7 +610,9 @@ WHERE (is_catalog_text_unique_index_oid(indexrelid) <>
 -- Look for illegal values in pg_range fields.
 SELECT r.rngtypid, r.rngsubtype
 FROM pg_range as r
-WHERE r.rngtypid = 0 OR r.rngsubtype = 0 OR r.rngsubopc = 0;
+WHERE r.rngtypid = 0 OR r.rngsubtype = 0 OR r.rngsubopc = 0
+    OR r.rngconstruct2 = 0 OR r.rngconstruct3 = 0
+    OR r.rngmltconstruct0 = 0 OR r.rngmltconstruct1 = 0 OR r.rngmltconstruct2 = 0;
  rngtypid | rngsubtype 
 ----------+------------
 (0 rows)
@@ -663,6 +665,61 @@ WHERE r.rngmultitypid IS NULL OR r.rngmultitypid = 0;
 ----------+------------+---------------
 (0 rows)
 
+-- check constructor function arguments and return types
+--
+-- proname and prosrc are not required to have these particular
+-- values, but this matches what DefineRange() produces and serves to
+-- sanity-check the catalog entries for built-in types.
+SELECT r.rngtypid, r.rngsubtype, p.proname
+FROM pg_range r JOIN pg_proc p ON p.oid = r.rngconstruct2 JOIN pg_type t ON r.rngtypid = t.oid
+WHERE p.pronargs != 2
+    OR p.proargtypes[0] != r.rngsubtype OR p.proargtypes[1] != r.rngsubtype
+    OR p.prorettype != r.rngtypid
+    OR p.proname != t.typname OR p.prosrc != 'range_constructor2';
+ rngtypid | rngsubtype | proname 
+----------+------------+---------
+(0 rows)
+
+SELECT r.rngtypid, r.rngsubtype, p.proname
+FROM pg_range r JOIN pg_proc p ON p.oid = r.rngconstruct3 JOIN pg_type t ON r.rngtypid = t.oid
+WHERE p.pronargs != 3
+    OR p.proargtypes[0] != r.rngsubtype OR p.proargtypes[1] != r.rngsubtype OR p.proargtypes[2] != 'pg_catalog.text'::regtype
+    OR p.prorettype != r.rngtypid
+    OR p.proname != t.typname OR p.prosrc != 'range_constructor3';
+ rngtypid | rngsubtype | proname 
+----------+------------+---------
+(0 rows)
+
+SELECT r.rngtypid, r.rngsubtype, p.proname
+FROM pg_range r JOIN pg_proc p ON p.oid = r.rngmltconstruct0 JOIN pg_type t ON r.rngmultitypid = t.oid
+WHERE p.pronargs != 0
+    OR p.prorettype != r.rngmultitypid
+    OR p.proname != t.typname OR p.prosrc != 'multirange_constructor0';
+ rngtypid | rngsubtype | proname 
+----------+------------+---------
+(0 rows)
+
+SELECT r.rngtypid, r.rngsubtype, p.proname
+FROM pg_range r JOIN pg_proc p ON p.oid = r.rngmltconstruct1 JOIN pg_type t ON r.rngmultitypid = t.oid
+WHERE p.pronargs != 1
+    OR p.proargtypes[0] != r.rngtypid
+    OR p.prorettype != r.rngmultitypid
+    OR p.proname != t.typname OR p.prosrc != 'multirange_constructor1';
+ rngtypid | rngsubtype | proname 
+----------+------------+---------
+(0 rows)
+
+SELECT r.rngtypid, r.rngsubtype, p.proname
+FROM pg_range r JOIN pg_proc p ON p.oid = r.rngmltconstruct2 JOIN pg_type t ON r.rngmultitypid = t.oid JOIN pg_type t2 ON r.rngtypid = t2.oid
+WHERE p.pronargs != 1
+    OR p.proargtypes[0] != t2.typarray
+    OR p.prorettype != r.rngmultitypid
+    OR p.proname != t.typname OR p.prosrc != 'multirange_constructor2';
+ rngtypid | rngsubtype | proname 
+----------+------------+---------
+(0 rows)
+
+-- ******************************************
 -- Create a table that holds all the known in-core data types and leave it
 -- around so as pg_upgrade is able to test their binary compatibility.
 CREATE TABLE tab_core_types AS SELECT

src/test/regress/sql/type_sanity.sql

@@ -451,7 +451,9 @@ WHERE (is_catalog_text_unique_index_oid(indexrelid) <>
 
 SELECT r.rngtypid, r.rngsubtype
 FROM pg_range as r
-WHERE r.rngtypid = 0 OR r.rngsubtype = 0 OR r.rngsubopc = 0;
+WHERE r.rngtypid = 0 OR r.rngsubtype = 0 OR r.rngsubopc = 0
+    OR r.rngconstruct2 = 0 OR r.rngconstruct3 = 0
+    OR r.rngmltconstruct0 = 0 OR r.rngmltconstruct1 = 0 OR r.rngmltconstruct2 = 0;
 
 -- rngcollation should be specified iff subtype is collatable
 
@@ -491,6 +493,49 @@ SELECT r.rngtypid, r.rngsubtype, r.rngmultitypid
 FROM pg_range r
 WHERE r.rngmultitypid IS NULL OR r.rngmultitypid = 0;
 
+-- check constructor function arguments and return types
+--
+-- proname and prosrc are not required to have these particular
+-- values, but this matches what DefineRange() produces and serves to
+-- sanity-check the catalog entries for built-in types.
+
+SELECT r.rngtypid, r.rngsubtype, p.proname
+FROM pg_range r JOIN pg_proc p ON p.oid = r.rngconstruct2 JOIN pg_type t ON r.rngtypid = t.oid
+WHERE p.pronargs != 2
+    OR p.proargtypes[0] != r.rngsubtype OR p.proargtypes[1] != r.rngsubtype
+    OR p.prorettype != r.rngtypid
+    OR p.proname != t.typname OR p.prosrc != 'range_constructor2';
+
+SELECT r.rngtypid, r.rngsubtype, p.proname
+FROM pg_range r JOIN pg_proc p ON p.oid = r.rngconstruct3 JOIN pg_type t ON r.rngtypid = t.oid
+WHERE p.pronargs != 3
+    OR p.proargtypes[0] != r.rngsubtype OR p.proargtypes[1] != r.rngsubtype OR p.proargtypes[2] != 'pg_catalog.text'::regtype
+    OR p.prorettype != r.rngtypid
+    OR p.proname != t.typname OR p.prosrc != 'range_constructor3';
+
+SELECT r.rngtypid, r.rngsubtype, p.proname
+FROM pg_range r JOIN pg_proc p ON p.oid = r.rngmltconstruct0 JOIN pg_type t ON r.rngmultitypid = t.oid
+WHERE p.pronargs != 0
+    OR p.prorettype != r.rngmultitypid
+    OR p.proname != t.typname OR p.prosrc != 'multirange_constructor0';
+
+SELECT r.rngtypid, r.rngsubtype, p.proname
+FROM pg_range r JOIN pg_proc p ON p.oid = r.rngmltconstruct1 JOIN pg_type t ON r.rngmultitypid = t.oid
+WHERE p.pronargs != 1
+    OR p.proargtypes[0] != r.rngtypid
+    OR p.prorettype != r.rngmultitypid
+    OR p.proname != t.typname OR p.prosrc != 'multirange_constructor1';
+
+SELECT r.rngtypid, r.rngsubtype, p.proname
+FROM pg_range r JOIN pg_proc p ON p.oid = r.rngmltconstruct2 JOIN pg_type t ON r.rngmultitypid = t.oid JOIN pg_type t2 ON r.rngtypid = t2.oid
+WHERE p.pronargs != 1
+    OR p.proargtypes[0] != t2.typarray
+    OR p.prorettype != r.rngmultitypid
+    OR p.proname != t.typname OR p.prosrc != 'multirange_constructor2';
+
+
+-- ******************************************
+
 -- Create a table that holds all the known in-core data types and leave it
 -- around so as pg_upgrade is able to test their binary compatibility.
 CREATE TABLE tab_core_types AS SELECT