Revert "Catalog NOT NULL constraints" and fallout

This reverts commit e056c557aef4 and minor later fixes thereof.

There's a few problems in this new feature -- most notably regarding
pg_upgrade behavior, but others as well.  This new feature is not in any
way critical on its own, so instead of scrambling to fix it we revert it
and try again in early 17 with these issues in mind.

Discussion: https://postgr.es/m/3801207.1681057430@sss.pgh.pa.us

3 files changed, 6 insertions, 14 deletions

diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index 54f3ddcd97e..f152a2e82b6 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -57,6 +57,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	202304075
+#define CATALOG_VERSION_NO	202304111
 
 #endif
diff --git a/src/include/catalog/heap.h b/src/include/catalog/heap.h
index 1683fdcb20a..d01ab504b6f 100644
--- a/src/include/catalog/heap.h
+++ b/src/include/catalog/heap.h
@@ -34,10 +34,10 @@ typedef struct RawColumnDefault
 
 typedef struct CookedConstraint
 {
-	ConstrType	contype;		/* CONSTR_DEFAULT, CONSTR_CHECK, CONSTR_NOTNULL */
+	ConstrType	contype;		/* CONSTR_DEFAULT or CONSTR_CHECK */
 	Oid			conoid;			/* constr OID if created, otherwise Invalid */
 	char	   *name;			/* name, or NULL if none */
-	AttrNumber	attnum;			/* which attr (only for NOTNULL, DEFAULT) */
+	AttrNumber	attnum;			/* which attr (only for DEFAULT) */
 	Node	   *expr;			/* transformed default or check expr */
 	bool		skip_validation;	/* skip validation? (only for CHECK) */
 	bool		is_local;		/* constraint has local (non-inherited) def */
@@ -113,9 +113,6 @@ extern List *AddRelationNewConstraints(Relation rel,
 									   bool is_local,
 									   bool is_internal,
 									   const char *queryString);
-extern List *AddRelationNotNullConstraints(Relation rel,
-										   List *constraints,
-										   List *additional_notnulls);
 
 extern void RelationClearMissing(Relation rel);
 extern void SetAttrMissing(Oid relid, char *attname, char *value);
diff --git a/src/include/catalog/pg_constraint.h b/src/include/catalog/pg_constraint.h
index 13573a3cf1a..16bf5f5576e 100644
--- a/src/include/catalog/pg_constraint.h
+++ b/src/include/catalog/pg_constraint.h
@@ -181,7 +181,6 @@ DECLARE_ARRAY_FOREIGN_KEY((confrelid, confkey), pg_attribute, (attrelid, attnum)
 /* Valid values for contype */
 #define CONSTRAINT_CHECK			'c'
 #define CONSTRAINT_FOREIGN			'f'
-#define CONSTRAINT_NOTNULL			'n'
 #define CONSTRAINT_PRIMARY			'p'
 #define CONSTRAINT_UNIQUE			'u'
 #define CONSTRAINT_TRIGGER			't'
@@ -238,6 +237,9 @@ extern Oid	CreateConstraintEntry(const char *constraintName,
 								  bool conNoInherit,
 								  bool is_internal);
 
+extern void RemoveConstraintById(Oid conId);
+extern void RenameConstraintById(Oid conId, const char *newname);
+
 extern bool ConstraintNameIsUsed(ConstraintCategory conCat, Oid objId,
 								 const char *conname);
 extern bool ConstraintNameExists(const char *conname, Oid namespaceid);
@@ -245,13 +247,6 @@ extern char *ChooseConstraintName(const char *name1, const char *name2,
 								  const char *label, Oid namespaceid,
 								  List *others);
 
-extern HeapTuple findNotNullConstraintAttnum(Relation rel, AttrNumber attnum);
-extern HeapTuple findNotNullConstraint(Relation rel, const char *colname);
-extern AttrNumber extractNotNullColumn(HeapTuple constrTup);
-
-extern void RemoveConstraintById(Oid conId);
-extern void RenameConstraintById(Oid conId, const char *newname);
-
 extern void AlterConstraintNamespaces(Oid ownerId, Oid oldNspId,
 									  Oid newNspId, bool isType, ObjectAddresses *objsMoved);
 extern void ConstraintSetParentConstraint(Oid childConstrId,