diff --git a/src/backend/catalog/Catalog.pm b/src/backend/catalog/Catalog.pm
index 1ba935cdf7..cdb0bee130 100644
--- a/src/backend/catalog/Catalog.pm
+++ b/src/backend/catalog/Catalog.pm
@@ -143,6 +143,7 @@ sub Catalogs
             elsif ($declaring_attributes)
             {
                 next if (/^{|^$/);
+                next if (/^#/);
                 if (/^}/)
                 {
                     undef $declaring_attributes;
@@ -150,6 +151,7 @@ sub Catalogs
                 else
                 {
                     my ($atttype, $attname) = split /\s+/, $_;
+                    die "parse error ($input_file)" unless $attname;
                     if (exists $RENAME_ATTTYPE{$atttype})
                     {
                         $atttype = $RENAME_ATTTYPE{$atttype};
diff --git a/src/include/catalog/genbki.h b/src/include/catalog/genbki.h
index 5fe3a5bdc4..bcf31e6c6b 100644
--- a/src/include/catalog/genbki.h
+++ b/src/include/catalog/genbki.h
@@ -22,6 +22,16 @@
 /* Introduces a catalog's structure definition */
 #define CATALOG(name,oid)	typedef struct CppConcat(FormData_,name)
 
+/*
+ * This is never defined; it's here only for documentation.
+ *
+ * Variable-length catalog fields (except possibly the first not nullable one)
+ * should not be visible in C structures, so they are made invisible by #ifdefs
+ * of an undefined symbol.  See also MARKNOTNULL in bootstrap.c for how this is
+ * handled.
+ */
+#undef CATALOG_VARLEN
+
 /* Options that may appear after CATALOG (on the same line) */
 #define BKI_BOOTSTRAP
 #define BKI_SHARED_RELATION
diff --git a/src/include/catalog/pg_aggregate.h b/src/include/catalog/pg_aggregate.h
index 4e10021765..0c8a20c005 100644
--- a/src/include/catalog/pg_aggregate.h
+++ b/src/include/catalog/pg_aggregate.h
@@ -44,7 +44,9 @@ CATALOG(pg_aggregate,2600) BKI_WITHOUT_OIDS
 	regproc		aggfinalfn;
 	Oid			aggsortop;
 	Oid			aggtranstype;
-	text		agginitval;		/* VARIABLE LENGTH FIELD */
+#ifdef CATALOG_VARLEN			/* variable-length fields start here */
+	text		agginitval;
+#endif
 } FormData_pg_aggregate;
 
 /* ----------------
diff --git a/src/include/catalog/pg_attrdef.h b/src/include/catalog/pg_attrdef.h
index 01f663c09d..ad770e410f 100644
--- a/src/include/catalog/pg_attrdef.h
+++ b/src/include/catalog/pg_attrdef.h
@@ -32,8 +32,10 @@ CATALOG(pg_attrdef,2604)
 {
 	Oid			adrelid;		/* OID of table containing attribute */
 	int2		adnum;			/* attnum of attribute */
+#ifdef CATALOG_VARLEN			/* variable-length fields start here */
 	pg_node_tree adbin;			/* nodeToString representation of default */
 	text		adsrc;			/* human-readable representation of default */
+#endif
 } FormData_pg_attrdef;
 
 /* ----------------
diff --git a/src/include/catalog/pg_attribute.h b/src/include/catalog/pg_attribute.h
index 5cb16f6c41..45e38e4dfc 100644
--- a/src/include/catalog/pg_attribute.h
+++ b/src/include/catalog/pg_attribute.h
@@ -145,11 +145,8 @@ CATALOG(pg_attribute,1249) BKI_BOOTSTRAP BKI_WITHOUT_OIDS BKI_ROWTYPE_OID(75) BK
 	/* attribute's collation */
 	Oid			attcollation;
 
-	/*
-	 * VARIABLE LENGTH FIELDS start here.  These fields may be NULL, too.
-	 *
-	 * NOTE: the following fields are not present in tuple descriptors!
-	 */
+#ifdef CATALOG_VARLEN			/* variable-length fields start here */
+	/* NOTE: The following fields are not present in tuple descriptors. */
 
 	/* Column-level access permissions */
 	aclitem		attacl[1];
@@ -159,6 +156,7 @@ CATALOG(pg_attribute,1249) BKI_BOOTSTRAP BKI_WITHOUT_OIDS BKI_ROWTYPE_OID(75) BK
 
 	/* Column-level FDW options */
 	text		attfdwoptions[1];
+#endif
 } FormData_pg_attribute;
 
 /*
diff --git a/src/include/catalog/pg_class.h b/src/include/catalog/pg_class.h
index 829f9b9c1d..3b01bb4365 100644
--- a/src/include/catalog/pg_class.h
+++ b/src/include/catalog/pg_class.h
@@ -68,14 +68,11 @@ CATALOG(pg_class,1259) BKI_BOOTSTRAP BKI_ROWTYPE_OID(83) BKI_SCHEMA_MACRO
 	bool		relhassubclass; /* has (or has had) derived classes */
 	TransactionId relfrozenxid; /* all Xids < this are frozen in this rel */
 
-	/*
-	 * VARIABLE LENGTH FIELDS start here.  These fields may be NULL, too.
-	 *
-	 * NOTE: these fields are not present in a relcache entry's rd_rel field.
-	 */
-
+#ifdef CATALOG_VARLEN			/* variable-length fields start here */
+	/* NOTE: These fields are not present in a relcache entry's rd_rel field. */
 	aclitem		relacl[1];		/* access permissions */
 	text		reloptions[1];	/* access-method-specific options */
+#endif
 } FormData_pg_class;
 
 /* Size of fixed part of pg_class tuples, not counting var-length fields */
diff --git a/src/include/catalog/pg_constraint.h b/src/include/catalog/pg_constraint.h
index c9628348a1..77015ae2f3 100644
--- a/src/include/catalog/pg_constraint.h
+++ b/src/include/catalog/pg_constraint.h
@@ -91,10 +91,7 @@ CATALOG(pg_constraint,2606)
 	/* Has a local definition and cannot be inherited */
 	bool		conisonly;
 
-	/*
-	 * VARIABLE LENGTH FIELDS start here.  These fields may be NULL, too.
-	 */
-
+#ifdef CATALOG_VARLEN			/* variable-length fields start here */
 	/*
 	 * Columns of conrelid that the constraint applies to, if known (this is
 	 * NULL for trigger constraints)
@@ -139,6 +136,7 @@ CATALOG(pg_constraint,2606)
 	 * If a check constraint, source-text representation of expression
 	 */
 	text		consrc;
+#endif
 } FormData_pg_constraint;
 
 /* ----------------
diff --git a/src/include/catalog/pg_database.h b/src/include/catalog/pg_database.h
index 57537c81f2..e8509f59bb 100644
--- a/src/include/catalog/pg_database.h
+++ b/src/include/catalog/pg_database.h
@@ -42,7 +42,9 @@ CATALOG(pg_database,1262) BKI_SHARED_RELATION BKI_ROWTYPE_OID(1248) BKI_SCHEMA_M
 	Oid			datlastsysoid;	/* highest OID to consider a system OID */
 	TransactionId datfrozenxid; /* all Xids < this are frozen in this DB */
 	Oid			dattablespace;	/* default table space for this DB */
-	aclitem		datacl[1];		/* access permissions (VAR LENGTH) */
+#ifdef CATALOG_VARLEN			/* variable-length fields start here */
+	aclitem		datacl[1];		/* access permissions */
+#endif
 } FormData_pg_database;
 
 /* ----------------
diff --git a/src/include/catalog/pg_db_role_setting.h b/src/include/catalog/pg_db_role_setting.h
index 192404316a..c6e2f3b4dc 100644
--- a/src/include/catalog/pg_db_role_setting.h
+++ b/src/include/catalog/pg_db_role_setting.h
@@ -35,7 +35,9 @@ CATALOG(pg_db_role_setting,2964) BKI_SHARED_RELATION BKI_WITHOUT_OIDS
 {
 	Oid			setdatabase;	/* database */
 	Oid			setrole;		/* role */
+#ifdef CATALOG_VARLEN			/* variable-length fields start here */
 	text		setconfig[1];	/* GUC settings to apply at login */
+#endif
 } FormData_pg_db_role_setting;
 
 typedef FormData_pg_db_role_setting *Form_pg_db_role_setting;
diff --git a/src/include/catalog/pg_default_acl.h b/src/include/catalog/pg_default_acl.h
index 9fd207d950..f36ce52519 100644
--- a/src/include/catalog/pg_default_acl.h
+++ b/src/include/catalog/pg_default_acl.h
@@ -32,12 +32,9 @@ CATALOG(pg_default_acl,826)
 	Oid			defaclrole;		/* OID of role owning this ACL */
 	Oid			defaclnamespace;	/* OID of namespace, or 0 for all */
 	char		defaclobjtype;	/* see DEFACLOBJ_xxx constants below */
-
-	/*
-	 * VARIABLE LENGTH FIELDS start here.
-	 */
-
+#ifdef CATALOG_VARLEN			/* variable-length fields start here */
 	aclitem		defaclacl[1];	/* permissions to add at CREATE time */
+#endif
 } FormData_pg_default_acl;
 
 /* ----------------
diff --git a/src/include/catalog/pg_description.h b/src/include/catalog/pg_description.h
index 0e06500763..352c517369 100644
--- a/src/include/catalog/pg_description.h
+++ b/src/include/catalog/pg_description.h
@@ -50,7 +50,9 @@ CATALOG(pg_description,2609) BKI_WITHOUT_OIDS
 	Oid			objoid;			/* OID of object itself */
 	Oid			classoid;		/* OID of table containing object */
 	int4		objsubid;		/* column number, or 0 if not used */
+#ifdef CATALOG_VARLEN			/* variable-length fields start here */
 	text		description;	/* description of object */
+#endif
 } FormData_pg_description;
 
 /* ----------------
diff --git a/src/include/catalog/pg_extension.h b/src/include/catalog/pg_extension.h
index 606ed9a2af..b07b43cf7e 100644
--- a/src/include/catalog/pg_extension.h
+++ b/src/include/catalog/pg_extension.h
@@ -34,15 +34,12 @@ CATALOG(pg_extension,3079)
 	Oid			extowner;		/* extension owner */
 	Oid			extnamespace;	/* namespace of contained objects */
 	bool		extrelocatable; /* if true, allow ALTER EXTENSION SET SCHEMA */
-
-	/*
-	 * VARIABLE LENGTH FIELDS start here.
-	 *
-	 * extversion should never be null, but the others can be.
-	 */
+#ifdef CATALOG_VARLEN			 /* variable-length fields start here */
+	/* extversion should never be null, but the others can be. */
 	text		extversion;		/* extension version name */
 	Oid			extconfig[1];	/* dumpable configuration tables */
 	text		extcondition[1];	/* WHERE clauses for config tables */
+#endif
 } FormData_pg_extension;
 
 /* ----------------
diff --git a/src/include/catalog/pg_foreign_data_wrapper.h b/src/include/catalog/pg_foreign_data_wrapper.h
index 90a51a2f4b..b6dd8eb7cc 100644
--- a/src/include/catalog/pg_foreign_data_wrapper.h
+++ b/src/include/catalog/pg_foreign_data_wrapper.h
@@ -34,11 +34,10 @@ CATALOG(pg_foreign_data_wrapper,2328)
 	Oid			fdwowner;		/* FDW owner */
 	Oid			fdwhandler;		/* handler function, or 0 if none */
 	Oid			fdwvalidator;	/* option validation function, or 0 if none */
-
-	/* VARIABLE LENGTH FIELDS start here. */
-
+#ifdef CATALOG_VARLEN			/* variable-length fields start here */
 	aclitem		fdwacl[1];		/* access permissions */
 	text		fdwoptions[1];	/* FDW options */
+#endif
 } FormData_pg_foreign_data_wrapper;
 
 /* ----------------
diff --git a/src/include/catalog/pg_foreign_server.h b/src/include/catalog/pg_foreign_server.h
index a96328cd27..dd1e65e02a 100644
--- a/src/include/catalog/pg_foreign_server.h
+++ b/src/include/catalog/pg_foreign_server.h
@@ -31,14 +31,12 @@ CATALOG(pg_foreign_server,1417)
 	NameData	srvname;		/* foreign server name */
 	Oid			srvowner;		/* server owner */
 	Oid			srvfdw;			/* server FDW */
-
-	/*
-	 * VARIABLE LENGTH FIELDS start here.  These fields may be NULL, too.
-	 */
+#ifdef CATALOG_VARLEN			/* variable-length fields start here */
 	text		srvtype;
 	text		srvversion;
 	aclitem		srvacl[1];		/* access permissions */
 	text		srvoptions[1];	/* FDW-specific options */
+#endif
 } FormData_pg_foreign_server;
 
 /* ----------------
diff --git a/src/include/catalog/pg_foreign_table.h b/src/include/catalog/pg_foreign_table.h
index 71992d3c42..9af983eb93 100644
--- a/src/include/catalog/pg_foreign_table.h
+++ b/src/include/catalog/pg_foreign_table.h
@@ -30,7 +30,9 @@ CATALOG(pg_foreign_table,3118) BKI_WITHOUT_OIDS
 {
 	Oid			ftrelid;		/* OID of foreign table */
 	Oid			ftserver;		/* OID of foreign server */
+#ifdef CATALOG_VARLEN			/* variable-length fields start here */
 	text		ftoptions[1];	/* FDW-specific options */
+#endif
 } FormData_pg_foreign_table;
 
 /* ----------------
diff --git a/src/include/catalog/pg_index.h b/src/include/catalog/pg_index.h
index 6c301ff17f..92ca22c686 100644
--- a/src/include/catalog/pg_index.h
+++ b/src/include/catalog/pg_index.h
@@ -42,8 +42,9 @@ CATALOG(pg_index,2610) BKI_WITHOUT_OIDS BKI_SCHEMA_MACRO
 	bool		indcheckxmin;	/* must we wait for xmin to be old? */
 	bool		indisready;		/* is this index ready for inserts? */
 
-	/* VARIABLE LENGTH FIELDS: */
+	/* variable-length fields start here, but we allow direct access to indkey */
 	int2vector	indkey;			/* column numbers of indexed cols, or 0 */
+#ifdef CATALOG_VARLEN
 	oidvector	indcollation;	/* collation identifiers */
 	oidvector	indclass;		/* opclass identifiers */
 	int2vector	indoption;		/* per-column flags (AM-specific meanings) */
@@ -52,6 +53,7 @@ CATALOG(pg_index,2610) BKI_WITHOUT_OIDS BKI_SCHEMA_MACRO
 								 * each zero entry in indkey[] */
 	pg_node_tree indpred;		/* expression tree for predicate, if a partial
 								 * index; else NULL */
+#endif
 } FormData_pg_index;
 
 /* ----------------
diff --git a/src/include/catalog/pg_language.h b/src/include/catalog/pg_language.h
index fd8ea0b79d..eb4ae5ab2d 100644
--- a/src/include/catalog/pg_language.h
+++ b/src/include/catalog/pg_language.h
@@ -37,7 +37,9 @@ CATALOG(pg_language,2612)
 	Oid			lanplcallfoid;	/* Call handler for PL */
 	Oid			laninline;		/* Optional anonymous-block handler function */
 	Oid			lanvalidator;	/* Optional validation function */
+#ifdef CATALOG_VARLEN			/* variable-length fields start here */
 	aclitem		lanacl[1];		/* Access privileges */
+#endif
 } FormData_pg_language;
 
 /* ----------------
diff --git a/src/include/catalog/pg_largeobject.h b/src/include/catalog/pg_largeobject.h
index 7c53e1e10e..b89d4ec1a9 100644
--- a/src/include/catalog/pg_largeobject.h
+++ b/src/include/catalog/pg_largeobject.h
@@ -32,6 +32,7 @@ CATALOG(pg_largeobject,2613) BKI_WITHOUT_OIDS
 {
 	Oid			loid;			/* Identifier of large object */
 	int4		pageno;			/* Page number (starting from 0) */
+	/* data has variable length, but we allow direct access; see inv_api.c */
 	bytea		data;			/* Data for page (may be zero-length) */
 } FormData_pg_largeobject;
 
diff --git a/src/include/catalog/pg_largeobject_metadata.h b/src/include/catalog/pg_largeobject_metadata.h
index dea4d1289c..c280176491 100644
--- a/src/include/catalog/pg_largeobject_metadata.h
+++ b/src/include/catalog/pg_largeobject_metadata.h
@@ -31,7 +31,9 @@
 CATALOG(pg_largeobject_metadata,2995)
 {
 	Oid			lomowner;		/* OID of the largeobject owner */
+#ifdef CATALOG_VARLEN			/* variable-length fields start here */
 	aclitem		lomacl[1];		/* access permissions */
+#endif
 } FormData_pg_largeobject_metadata;
 
 /* ----------------
diff --git a/src/include/catalog/pg_namespace.h b/src/include/catalog/pg_namespace.h
index 52a97f1a9e..aad76a1452 100644
--- a/src/include/catalog/pg_namespace.h
+++ b/src/include/catalog/pg_namespace.h
@@ -37,7 +37,9 @@ CATALOG(pg_namespace,2615)
 {
 	NameData	nspname;
 	Oid			nspowner;
-	aclitem		nspacl[1];		/* VARIABLE LENGTH FIELD */
+#ifdef CATALOG_VARLEN			/* variable-length fields start here */
+	aclitem		nspacl[1];
+#endif
 } FormData_pg_namespace;
 
 /* ----------------
diff --git a/src/include/catalog/pg_pltemplate.h b/src/include/catalog/pg_pltemplate.h
index ce249c0e0f..00abd53370 100644
--- a/src/include/catalog/pg_pltemplate.h
+++ b/src/include/catalog/pg_pltemplate.h
@@ -33,11 +33,13 @@ CATALOG(pg_pltemplate,1136) BKI_SHARED_RELATION BKI_WITHOUT_OIDS
 	NameData	tmplname;		/* name of PL */
 	bool		tmpltrusted;	/* PL is trusted? */
 	bool		tmpldbacreate;	/* PL is installable by db owner? */
+#ifdef CATALOG_VARLEN			/* variable-length fields start here */
 	text		tmplhandler;	/* name of call handler function */
 	text		tmplinline;		/* name of anonymous-block handler, or NULL */
 	text		tmplvalidator;	/* name of validator function, or NULL */
 	text		tmpllibrary;	/* path of shared library */
 	aclitem		tmplacl[1];		/* access privileges for template */
+#endif
 } FormData_pg_pltemplate;
 
 /* ----------------
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index ba4f5b6034..5e880d2a4d 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -53,8 +53,9 @@ CATALOG(pg_proc,1255) BKI_BOOTSTRAP BKI_ROWTYPE_OID(81) BKI_SCHEMA_MACRO
 	int2		pronargdefaults;	/* number of arguments with defaults */
 	Oid			prorettype;		/* OID of result type */
 
-	/* VARIABLE LENGTH FIELDS: */
+	/* variable-length fields start here, but we allow direct access to proargtypes */
 	oidvector	proargtypes;	/* parameter types (excludes OUT params) */
+#ifdef CATALOG_VARLEN
 	Oid			proallargtypes[1];		/* all param types (NULL if IN only) */
 	char		proargmodes[1]; /* parameter modes (NULL if IN only) */
 	text		proargnames[1]; /* parameter names (NULL if no names) */
@@ -64,6 +65,7 @@ CATALOG(pg_proc,1255) BKI_BOOTSTRAP BKI_ROWTYPE_OID(81) BKI_SCHEMA_MACRO
 	text		probin;			/* secondary procedure info (can be NULL) */
 	text		proconfig[1];	/* procedure-local GUC settings */
 	aclitem		proacl[1];		/* access permissions */
+#endif
 } FormData_pg_proc;
 
 /* ----------------
diff --git a/src/include/catalog/pg_rewrite.h b/src/include/catalog/pg_rewrite.h
index eb16b2dc2d..e04ba81b3c 100644
--- a/src/include/catalog/pg_rewrite.h
+++ b/src/include/catalog/pg_rewrite.h
@@ -39,10 +39,10 @@ CATALOG(pg_rewrite,2618)
 	char		ev_type;
 	char		ev_enabled;
 	bool		is_instead;
-
-	/* NB: remaining fields must be accessed via heap_getattr */
+#ifdef CATALOG_VARLEN			/* variable-length fields start here */
 	pg_node_tree ev_qual;
 	pg_node_tree ev_action;
+#endif
 } FormData_pg_rewrite;
 
 /* ----------------
diff --git a/src/include/catalog/pg_seclabel.h b/src/include/catalog/pg_seclabel.h
index b468d6924b..101ec3c111 100644
--- a/src/include/catalog/pg_seclabel.h
+++ b/src/include/catalog/pg_seclabel.h
@@ -25,8 +25,10 @@ CATALOG(pg_seclabel,3596) BKI_WITHOUT_OIDS
 	Oid			objoid;			/* OID of the object itself */
 	Oid			classoid;		/* OID of table containing the object */
 	int4		objsubid;		/* column number, or 0 if not used */
+#ifdef CATALOG_VARLEN			/* variable-length fields start here */
 	text		provider;		/* name of label provider */
 	text		label;			/* security label of the object */
+#endif
 } FormData_pg_seclabel;
 
 /* ----------------
diff --git a/src/include/catalog/pg_shdescription.h b/src/include/catalog/pg_shdescription.h
index 6d0ee3bcbb..377f4337d9 100644
--- a/src/include/catalog/pg_shdescription.h
+++ b/src/include/catalog/pg_shdescription.h
@@ -42,7 +42,9 @@ CATALOG(pg_shdescription,2396) BKI_SHARED_RELATION BKI_WITHOUT_OIDS
 {
 	Oid			objoid;			/* OID of object itself */
 	Oid			classoid;		/* OID of table containing object */
+#ifdef CATALOG_VARLEN			/* variable-length fields start here */
 	text		description;	/* description of object */
+#endif
 } FormData_pg_shdescription;
 
 /* ----------------
diff --git a/src/include/catalog/pg_shseclabel.h b/src/include/catalog/pg_shseclabel.h
index 235564f5dd..d7c49e78bb 100644
--- a/src/include/catalog/pg_shseclabel.h
+++ b/src/include/catalog/pg_shseclabel.h
@@ -24,8 +24,10 @@ CATALOG(pg_shseclabel,3592) BKI_SHARED_RELATION BKI_WITHOUT_OIDS
 {
 	Oid			objoid;		/* OID of the shared object itself */
 	Oid			classoid;	/* OID of table containing the shared object */
+#ifdef CATALOG_VARLEN		/* variable-length fields start here */
 	text		provider;	/* name of label provider */
 	text		label;		/* security label of the object */
+#endif
 } FormData_pg_shseclabel;
 
 /* ----------------
diff --git a/src/include/catalog/pg_statistic.h b/src/include/catalog/pg_statistic.h
index 7d1d127ec6..0b15b001b4 100644
--- a/src/include/catalog/pg_statistic.h
+++ b/src/include/catalog/pg_statistic.h
@@ -116,6 +116,7 @@ CATALOG(pg_statistic,2619) BKI_WITHOUT_OIDS
 	float4		stanumbers3[1];
 	float4		stanumbers4[1];
 
+#ifdef CATALOG_VARLEN			/* variable-length fields start here */
 	/*
 	 * Values in these arrays are values of the column's data type.  We
 	 * presently have to cheat quite a bit to allow polymorphic arrays of this
@@ -125,6 +126,7 @@ CATALOG(pg_statistic,2619) BKI_WITHOUT_OIDS
 	anyarray	stavalues2;
 	anyarray	stavalues3;
 	anyarray	stavalues4;
+#endif
 } FormData_pg_statistic;
 
 #define STATISTIC_NUM_SLOTS  4
diff --git a/src/include/catalog/pg_tablespace.h b/src/include/catalog/pg_tablespace.h
index a6a068659b..0650a5fbae 100644
--- a/src/include/catalog/pg_tablespace.h
+++ b/src/include/catalog/pg_tablespace.h
@@ -32,8 +32,10 @@ CATALOG(pg_tablespace,1213) BKI_SHARED_RELATION
 {
 	NameData	spcname;		/* tablespace name */
 	Oid			spcowner;		/* owner of tablespace */
-	aclitem		spcacl[1];		/* access permissions (VAR LENGTH) */
+#ifdef CATALOG_VARLEN			/* variable-length fields start here */
+	aclitem		spcacl[1];		/* access permissions */
 	text		spcoptions[1];	/* per-tablespace options */
+#endif
 } FormData_pg_tablespace;
 
 /* ----------------
diff --git a/src/include/catalog/pg_trigger.h b/src/include/catalog/pg_trigger.h
index 1f29d21f63..0ee5b8af8d 100644
--- a/src/include/catalog/pg_trigger.h
+++ b/src/include/catalog/pg_trigger.h
@@ -50,10 +50,13 @@ CATALOG(pg_trigger,2620)
 	bool		tginitdeferred; /* constraint trigger is deferred initially */
 	int2		tgnargs;		/* # of extra arguments in tgargs */
 
-	/* VARIABLE LENGTH FIELDS (note: tgattr and tgargs must not be null) */
+	/* Variable-length fields start here, but we allow direct access to tgattr.
+	 * Note: tgattr and tgargs must not be null. */
 	int2vector	tgattr;			/* column numbers, if trigger is on columns */
+#ifdef CATALOG_VARLEN
 	bytea		tgargs;			/* first\000second\000tgnargs\000 */
 	pg_node_tree tgqual;		/* WHEN expression, or NULL if none */
+#endif
 } FormData_pg_trigger;
 
 /* ----------------
diff --git a/src/include/catalog/pg_ts_dict.h b/src/include/catalog/pg_ts_dict.h
index 5036b8cfd2..31fcdd8896 100644
--- a/src/include/catalog/pg_ts_dict.h
+++ b/src/include/catalog/pg_ts_dict.h
@@ -36,7 +36,9 @@ CATALOG(pg_ts_dict,3600)
 	Oid			dictnamespace;	/* name space */
 	Oid			dictowner;		/* owner */
 	Oid			dicttemplate;	/* dictionary's template */
+#ifdef CATALOG_VARLEN			/* variable-length fields start here */
 	text		dictinitoption; /* options passed to dict_init() */
+#endif
 } FormData_pg_ts_dict;
 
 typedef FormData_pg_ts_dict *Form_pg_ts_dict;
diff --git a/src/include/catalog/pg_type.h b/src/include/catalog/pg_type.h
index e12efe45db..d9855a79f8 100644
--- a/src/include/catalog/pg_type.h
+++ b/src/include/catalog/pg_type.h
@@ -200,12 +200,13 @@ CATALOG(pg_type,1247) BKI_BOOTSTRAP BKI_ROWTYPE_OID(71) BKI_SCHEMA_MACRO
 	 */
 	Oid			typcollation;
 
+#ifdef CATALOG_VARLEN			/* variable-length fields start here */
 	/*
 	 * If typdefaultbin is not NULL, it is the nodeToString representation of
 	 * a default expression for the type.  Currently this is only used for
 	 * domains.
 	 */
-	pg_node_tree typdefaultbin; /* VARIABLE LENGTH FIELD */
+	pg_node_tree typdefaultbin;
 
 	/*
 	 * typdefault is NULL if the type has no associated default value. If
@@ -215,12 +216,13 @@ CATALOG(pg_type,1247) BKI_BOOTSTRAP BKI_ROWTYPE_OID(71) BKI_SCHEMA_MACRO
 	 * external representation of the type's default value, which may be fed
 	 * to the type's input converter to produce a constant.
 	 */
-	text		typdefault;		/* VARIABLE LENGTH FIELD */
+	text		typdefault;
 
 	/*
 	 * Access permissions
 	 */
-	aclitem		typacl[1];		/* VARIABLE LENGTH FIELD */
+	aclitem		typacl[1];
+#endif
 } FormData_pg_type;
 
 /* ----------------
diff --git a/src/include/catalog/pg_user_mapping.h b/src/include/catalog/pg_user_mapping.h
index 551000fcfc..1d2f9b0bd0 100644
--- a/src/include/catalog/pg_user_mapping.h
+++ b/src/include/catalog/pg_user_mapping.h
@@ -32,11 +32,9 @@ CATALOG(pg_user_mapping,1418)
 								 * wanted */
 	Oid			umserver;		/* server of this mapping */
 
-	/*
-	 * VARIABLE LENGTH FIELDS start here.  These fields may be NULL, too.
-	 */
-
+#ifdef CATALOG_VARLEN			/* variable-length fields start here */
 	text		umoptions[1];	/* user mapping options */
+#endif
 } FormData_pg_user_mapping;
 
 /* ----------------