Do some minor code refactoring in preparation for changing the APIs of

find_inheritance_children() and find_all_inheritors().  I got annoyed that
these are buried inside the planner but mostly used elsewhere.  So, create
a new file catalog/pg_inherits.c and put them there, along with a couple
of other functions that search pg_inherits.

The code that modifies pg_inherits is (still) in tablecmds.c --- it's
kind of entangled with unrelated code that modifies pg_depend and other
stuff, so pulling it out seemed like a bigger change than I wanted to make
right now.  But this file provides a natural home for it if anyone ever
gets around to that.

This commit just moves code around; it doesn't change anything, except
I succumbed to the temptation to make a couple of trivial optimizations
in typeInheritsFrom().

src/backend/catalog/Makefile

@@ -2,7 +2,7 @@
 #
 # Makefile for backend/catalog
 #
-# $PostgreSQL: pgsql/src/backend/catalog/Makefile,v 1.69 2009/02/09 20:57:59 alvherre Exp $
+# $PostgreSQL: pgsql/src/backend/catalog/Makefile,v 1.70 2009/05/12 00:56:05 tgl Exp $
 #
 #-------------------------------------------------------------------------
 
@@ -12,8 +12,8 @@ include $(top_builddir)/src/Makefile.global
 
 OBJS = catalog.o dependency.o heap.o index.o indexing.o namespace.o aclchk.o \
        pg_aggregate.o pg_constraint.o pg_conversion.o pg_depend.o pg_enum.o \
-       pg_largeobject.o pg_namespace.o pg_operator.o pg_proc.o pg_shdepend.o \
-       pg_type.o storage.o toasting.o
+       pg_inherits.o pg_largeobject.o pg_namespace.o pg_operator.o pg_proc.o \
+       pg_shdepend.o pg_type.o storage.o toasting.o
 
 BKIFILES = postgres.bki postgres.description postgres.shdescription
 

src/backend/catalog/pg_inherits.c

+/*-------------------------------------------------------------------------
+ *
+ * pg_inherits.c
+ *	  routines to support manipulation of the pg_inherits relation
+ *
+ * Note: currently, this module only contains inquiry functions; the actual
+ * creation and deletion of pg_inherits entries is done in tablecmds.c.
+ * Perhaps someday that code should be moved here, but it'd have to be
+ * disentangled from other stuff such as pg_depend updates.
+ *
+ * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  $PostgreSQL: pgsql/src/backend/catalog/pg_inherits.c,v 1.1 2009/05/12 00:56:05 tgl Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "access/heapam.h"
+#include "catalog/pg_class.h"
+#include "catalog/pg_inherits.h"
+#include "parser/parse_type.h"
+#include "utils/fmgroids.h"
+#include "utils/syscache.h"
+#include "utils/tqual.h"
+
+
+/*
+ * find_inheritance_children
+ *
+ * Returns a list containing the OIDs of all relations which
+ * inherit *directly* from the relation with OID 'parentrelId'.
+ */
+List *
+find_inheritance_children(Oid parentrelId)
+{
+	List	   *list = NIL;
+	Relation	relation;
+	HeapScanDesc scan;
+	ScanKeyData key[1];
+	HeapTuple	inheritsTuple;
+	Oid			inhrelid;
+
+	/*
+	 * Can skip the scan if pg_class shows the relation has never had a
+	 * subclass.
+	 */
+	if (!has_subclass(parentrelId))
+		return NIL;
+
+	/*
+	 * XXX might be a good idea to create an index on pg_inherits' inhparent
+	 * field, so that we can use an indexscan instead of sequential scan here.
+	 * However, in typical databases pg_inherits won't have enough entries to
+	 * justify an indexscan...
+	 */
+	relation = heap_open(InheritsRelationId, AccessShareLock);
+	ScanKeyInit(&key[0],
+				Anum_pg_inherits_inhparent,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(parentrelId));
+	scan = heap_beginscan(relation, SnapshotNow, 1, key);
+	while ((inheritsTuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
+	{
+		inhrelid = ((Form_pg_inherits) GETSTRUCT(inheritsTuple))->inhrelid;
+		list = lappend_oid(list, inhrelid);
+	}
+	heap_endscan(scan);
+	heap_close(relation, AccessShareLock);
+	return list;
+}
+
+
+/*
+ * find_all_inheritors -
+ *		Returns a list of relation OIDs including the given rel plus
+ *		all relations that inherit from it, directly or indirectly.
+ */
+List *
+find_all_inheritors(Oid parentrelId)
+{
+	List	   *rels_list;
+	ListCell   *l;
+
+	/*
+	 * We build a list starting with the given rel and adding all direct and
+	 * indirect children.  We can use a single list as both the record of
+	 * already-found rels and the agenda of rels yet to be scanned for more
+	 * children.  This is a bit tricky but works because the foreach() macro
+	 * doesn't fetch the next list element until the bottom of the loop.
+	 */
+	rels_list = list_make1_oid(parentrelId);
+
+	foreach(l, rels_list)
+	{
+		Oid			currentrel = lfirst_oid(l);
+		List	   *currentchildren;
+
+		/* Get the direct children of this rel */
+		currentchildren = find_inheritance_children(currentrel);
+
+		/*
+		 * Add to the queue only those children not already seen. This avoids
+		 * making duplicate entries in case of multiple inheritance paths from
+		 * the same parent.  (It'll also keep us from getting into an infinite
+		 * loop, though theoretically there can't be any cycles in the
+		 * inheritance graph anyway.)
+		 */
+		rels_list = list_concat_unique_oid(rels_list, currentchildren);
+	}
+
+	return rels_list;
+}
+
+
+/*
+ * has_subclass - does this relation have any children?
+ *
+ * In the current implementation, has_subclass returns whether a
+ * particular class *might* have a subclass. It will not return the
+ * correct result if a class had a subclass which was later dropped.
+ * This is because relhassubclass in pg_class is not updated when a
+ * subclass is dropped, primarily because of concurrency concerns.
+ *
+ * Currently has_subclass is only used as an efficiency hack to skip
+ * unnecessary inheritance searches, so this is OK.
+ *
+ * Although this doesn't actually touch pg_inherits, it seems reasonable
+ * to keep it here since it's normally used with the other routines here.
+ */
+bool
+has_subclass(Oid relationId)
+{
+	HeapTuple	tuple;
+	bool		result;
+
+	tuple = SearchSysCache(RELOID,
+						   ObjectIdGetDatum(relationId),
+						   0, 0, 0);
+	if (!HeapTupleIsValid(tuple))
+		elog(ERROR, "cache lookup failed for relation %u", relationId);
+
+	result = ((Form_pg_class) GETSTRUCT(tuple))->relhassubclass;
+	ReleaseSysCache(tuple);
+	return result;
+}
+
+
+/*
+ * Given two type OIDs, determine whether the first is a complex type
+ * (class type) that inherits from the second.
+ */
+bool
+typeInheritsFrom(Oid subclassTypeId, Oid superclassTypeId)
+{
+	bool		result = false;
+	Oid			subclassRelid;
+	Oid			superclassRelid;
+	Relation	inhrel;
+	List	   *visited,
+			   *queue;
+	ListCell   *queue_item;
+
+	/* We need to work with the associated relation OIDs */
+	subclassRelid = typeidTypeRelid(subclassTypeId);
+	if (subclassRelid == InvalidOid)
+		return false;			/* not a complex type */
+	superclassRelid = typeidTypeRelid(superclassTypeId);
+	if (superclassRelid == InvalidOid)
+		return false;			/* not a complex type */
+
+	/* No point in searching if the superclass has no subclasses */
+	if (!has_subclass(superclassRelid))
+		return false;
+
+	/*
+	 * Begin the search at the relation itself, so add its relid to the queue.
+	 */
+	queue = list_make1_oid(subclassRelid);
+	visited = NIL;
+
+	inhrel = heap_open(InheritsRelationId, AccessShareLock);
+
+	/*
+	 * Use queue to do a breadth-first traversal of the inheritance graph from
+	 * the relid supplied up to the root.  Notice that we append to the queue
+	 * inside the loop --- this is okay because the foreach() macro doesn't
+	 * advance queue_item until the next loop iteration begins.
+	 */
+	foreach(queue_item, queue)
+	{
+		Oid			this_relid = lfirst_oid(queue_item);
+		ScanKeyData skey;
+		HeapScanDesc inhscan;
+		HeapTuple	inhtup;
+
+		/*
+		 * If we've seen this relid already, skip it.  This avoids extra
+		 * work in multiple-inheritance scenarios, and also protects us
+		 * from an infinite loop in case there is a cycle in pg_inherits
+		 * (though theoretically that shouldn't happen).
+		 */
+		if (list_member_oid(visited, this_relid))
+			continue;
+
+		/*
+		 * Okay, this is a not-yet-seen relid. Add it to the list of
+		 * already-visited OIDs, then find all the types this relid inherits
+		 * from and add them to the queue.
+		 */
+		visited = lappend_oid(visited, this_relid);
+
+		ScanKeyInit(&skey,
+					Anum_pg_inherits_inhrelid,
+					BTEqualStrategyNumber, F_OIDEQ,
+					ObjectIdGetDatum(this_relid));
+
+		inhscan = heap_beginscan(inhrel, SnapshotNow, 1, &skey);
+
+		while ((inhtup = heap_getnext(inhscan, ForwardScanDirection)) != NULL)
+		{
+			Form_pg_inherits inh = (Form_pg_inherits) GETSTRUCT(inhtup);
+			Oid			inhparent = inh->inhparent;
+
+			/* If this is the target superclass, we're done */
+			if (inhparent == superclassRelid)
+			{
+				result = true;
+				break;
+			}
+
+			/* Else add to queue */
+			queue = lappend_oid(queue, inhparent);
+		}
+
+		heap_endscan(inhscan);
+
+		if (result)
+			break;
+	}
+
+	/* clean up ... */
+	heap_close(inhrel, AccessShareLock);
+
+	list_free(visited);
+	list_free(queue);
+
+	return result;
+}

src/backend/commands/lockcmds.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/lockcmds.c,v 1.21 2009/01/12 08:54:26 petere Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/lockcmds.c,v 1.22 2009/05/12 00:56:05 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -16,9 +16,9 @@
 
 #include "access/heapam.h"
 #include "catalog/namespace.h"
+#include "catalog/pg_inherits.h"
 #include "commands/lockcmds.h"
 #include "miscadmin.h"
-#include "optimizer/prep.h"
 #include "parser/parse_clause.h"
 #include "utils/acl.h"
 #include "utils/lsyscache.h"

src/backend/commands/tablecmds.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.282 2009/05/07 22:58:28 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.283 2009/05/12 00:56:05 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -50,8 +50,6 @@
 #include "nodes/nodeFuncs.h"
 #include "nodes/parsenodes.h"
 #include "optimizer/clauses.h"
-#include "optimizer/plancat.h"
-#include "optimizer/prep.h"
 #include "parser/gramparse.h"
 #include "parser/parse_clause.h"
 #include "parser/parse_coerce.h"
@@ -1873,7 +1871,6 @@ renameatt(Oid myrelid,
 		ListCell   *child;
 		List	   *children;
 
-		/* this routine is actually in the planner */
 		children = find_all_inheritors(myrelid);
 
 		/*
@@ -3292,7 +3289,6 @@ ATSimpleRecursion(List **wqueue, Relation rel,
 		ListCell   *child;
 		List	   *children;
 
-		/* this routine is actually in the planner */
 		children = find_all_inheritors(relid);
 
 		/*
@@ -3331,7 +3327,6 @@ ATOneLevelRecursion(List **wqueue, Relation rel,
 	ListCell   *child;
 	List	   *children;
 
-	/* this routine is actually in the planner */
 	children = find_inheritance_children(relid);
 
 	foreach(child, children)

src/backend/optimizer/prep/prepunion.c

@@ -22,7 +22,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/prep/prepunion.c,v 1.168 2009/03/31 22:12:48 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/prep/prepunion.c,v 1.169 2009/05/12 00:56:05 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -32,6 +32,7 @@
 #include "access/heapam.h"
 #include "access/sysattr.h"
 #include "catalog/namespace.h"
+#include "catalog/pg_inherits.h"
 #include "catalog/pg_type.h"
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
@@ -39,7 +40,6 @@
 #include "optimizer/cost.h"
 #include "optimizer/pathnode.h"
 #include "optimizer/paths.h"
-#include "optimizer/plancat.h"
 #include "optimizer/planmain.h"
 #include "optimizer/planner.h"
 #include "optimizer/prep.h"
@@ -1081,47 +1081,6 @@ generate_setop_grouplist(SetOperationStmt *op, List *targetlist)
 }
 
 
-/*
- * find_all_inheritors -
- *		Returns a list of relation OIDs including the given rel plus
- *		all relations that inherit from it, directly or indirectly.
- */
-List *
-find_all_inheritors(Oid parentrel)
-{
-	List	   *rels_list;
-	ListCell   *l;
-
-	/*
-	 * We build a list starting with the given rel and adding all direct and
-	 * indirect children.  We can use a single list as both the record of
-	 * already-found rels and the agenda of rels yet to be scanned for more
-	 * children.  This is a bit tricky but works because the foreach() macro
-	 * doesn't fetch the next list element until the bottom of the loop.
-	 */
-	rels_list = list_make1_oid(parentrel);
-
-	foreach(l, rels_list)
-	{
-		Oid			currentrel = lfirst_oid(l);
-		List	   *currentchildren;
-
-		/* Get the direct children of this rel */
-		currentchildren = find_inheritance_children(currentrel);
-
-		/*
-		 * Add to the queue only those children not already seen. This avoids
-		 * making duplicate entries in case of multiple inheritance paths from
-		 * the same parent.  (It'll also keep us from getting into an infinite
-		 * loop, though theoretically there can't be any cycles in the
-		 * inheritance graph anyway.)
-		 */
-		rels_list = list_concat_unique_oid(rels_list, currentchildren);
-	}
-
-	return rels_list;
-}
-
 /*
  * expand_inherited_tables
  *		Expand each rangetable entry that represents an inheritance set

src/backend/optimizer/util/plancat.c

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/util/plancat.c,v 1.156 2009/03/05 23:06:45 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/util/plancat.c,v 1.157 2009/05/12 00:56:05 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -22,7 +22,6 @@
 #include "access/sysattr.h"
 #include "access/transam.h"
 #include "catalog/catalog.h"
-#include "catalog/pg_inherits.h"
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
 #include "nodes/nodeFuncs.h"
@@ -35,12 +34,9 @@
 #include "parser/parsetree.h"
 #include "rewrite/rewriteManip.h"
 #include "storage/bufmgr.h"
-#include "utils/fmgroids.h"
 #include "utils/lsyscache.h"
 #include "utils/rel.h"
 #include "utils/snapmgr.h"
-#include "utils/syscache.h"
-#include "utils/tqual.h"
 
 
 /* GUC parameter */
@@ -850,79 +846,6 @@ join_selectivity(PlannerInfo *root,
 	return (Selectivity) result;
 }
 
-/*
- * find_inheritance_children
- *
- * Returns a list containing the OIDs of all relations which
- * inherit *directly* from the relation with OID 'inhparent'.
- *
- * XXX might be a good idea to create an index on pg_inherits' inhparent
- * field, so that we can use an indexscan instead of sequential scan here.
- * However, in typical databases pg_inherits won't have enough entries to
- * justify an indexscan...
- */
-List *
-find_inheritance_children(Oid inhparent)
-{
-	List	   *list = NIL;
-	Relation	relation;
-	HeapScanDesc scan;
-	HeapTuple	inheritsTuple;
-	Oid			inhrelid;
-	ScanKeyData key[1];
-
-	/*
-	 * Can skip the scan if pg_class shows the relation has never had a
-	 * subclass.
-	 */
-	if (!has_subclass(inhparent))
-		return NIL;
-
-	ScanKeyInit(&key[0],
-				Anum_pg_inherits_inhparent,
-				BTEqualStrategyNumber, F_OIDEQ,
-				ObjectIdGetDatum(inhparent));
-	relation = heap_open(InheritsRelationId, AccessShareLock);
-	scan = heap_beginscan(relation, SnapshotNow, 1, key);
-	while ((inheritsTuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
-	{
-		inhrelid = ((Form_pg_inherits) GETSTRUCT(inheritsTuple))->inhrelid;
-		list = lappend_oid(list, inhrelid);
-	}
-	heap_endscan(scan);
-	heap_close(relation, AccessShareLock);
-	return list;
-}
-
-/*
- * has_subclass
- *
- * In the current implementation, has_subclass returns whether a
- * particular class *might* have a subclass. It will not return the
- * correct result if a class had a subclass which was later dropped.
- * This is because relhassubclass in pg_class is not updated when a
- * subclass is dropped, primarily because of concurrency concerns.
- *
- * Currently has_subclass is only used as an efficiency hack to skip
- * unnecessary inheritance searches, so this is OK.
- */
-bool
-has_subclass(Oid relationId)
-{
-	HeapTuple	tuple;
-	bool		result;
-
-	tuple = SearchSysCache(RELOID,
-						   ObjectIdGetDatum(relationId),
-						   0, 0, 0);
-	if (!HeapTupleIsValid(tuple))
-		elog(ERROR, "cache lookup failed for relation %u", relationId);
-
-	result = ((Form_pg_class) GETSTRUCT(tuple))->relhassubclass;
-	ReleaseSysCache(tuple);
-	return result;
-}
-
 /*
  * has_unique_index
  *

src/backend/parser/parse_coerce.c

@@ -8,13 +8,14 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/parse_coerce.c,v 2.174 2009/01/01 17:23:45 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/parse_coerce.c,v 2.175 2009/05/12 00:56:05 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
 #include "postgres.h"
 
 #include "catalog/pg_cast.h"
+#include "catalog/pg_inherits.h"
 #include "catalog/pg_proc.h"
 #include "catalog/pg_type.h"
 #include "nodes/makefuncs.h"

src/backend/parser/parse_func.c

@@ -8,14 +8,12 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/parse_func.c,v 1.213 2009/04/24 16:09:50 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/parse_func.c,v 1.214 2009/05/12 00:56:05 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
 #include "postgres.h"
 
-#include "access/heapam.h"
-#include "catalog/pg_inherits.h"
 #include "catalog/pg_proc.h"
 #include "catalog/pg_type.h"
 #include "funcapi.h"
@@ -28,10 +26,8 @@
 #include "parser/parse_target.h"
 #include "parser/parse_type.h"
 #include "utils/builtins.h"
-#include "utils/fmgroids.h"
 #include "utils/lsyscache.h"
 #include "utils/syscache.h"
-#include "utils/tqual.h"
 
 
 static Oid	FuncNameAsType(List *funcname);
@@ -1037,98 +1033,6 @@ func_get_detail(List *funcname,
 }
 
 
-/*
- * Given two type OIDs, determine whether the first is a complex type
- * (class type) that inherits from the second.
- */
-bool
-typeInheritsFrom(Oid subclassTypeId, Oid superclassTypeId)
-{
-	bool		result = false;
-	Oid			relid;
-	Relation	inhrel;
-	List	   *visited,
-			   *queue;
-	ListCell   *queue_item;
-
-	if (!ISCOMPLEX(subclassTypeId) || !ISCOMPLEX(superclassTypeId))
-		return false;
-	relid = typeidTypeRelid(subclassTypeId);
-	if (relid == InvalidOid)
-		return false;
-
-	/*
-	 * Begin the search at the relation itself, so add relid to the queue.
-	 */
-	queue = list_make1_oid(relid);
-	visited = NIL;
-
-	inhrel = heap_open(InheritsRelationId, AccessShareLock);
-
-	/*
-	 * Use queue to do a breadth-first traversal of the inheritance graph from
-	 * the relid supplied up to the root.  Notice that we append to the queue
-	 * inside the loop --- this is okay because the foreach() macro doesn't
-	 * advance queue_item until the next loop iteration begins.
-	 */
-	foreach(queue_item, queue)
-	{
-		Oid			this_relid = lfirst_oid(queue_item);
-		ScanKeyData skey;
-		HeapScanDesc inhscan;
-		HeapTuple	inhtup;
-
-		/* If we've seen this relid already, skip it */
-		if (list_member_oid(visited, this_relid))
-			continue;
-
-		/*
-		 * Okay, this is a not-yet-seen relid. Add it to the list of
-		 * already-visited OIDs, then find all the types this relid inherits
-		 * from and add them to the queue. The one exception is we don't add
-		 * the original relation to 'visited'.
-		 */
-		if (queue_item != list_head(queue))
-			visited = lappend_oid(visited, this_relid);
-
-		ScanKeyInit(&skey,
-					Anum_pg_inherits_inhrelid,
-					BTEqualStrategyNumber, F_OIDEQ,
-					ObjectIdGetDatum(this_relid));
-
-		inhscan = heap_beginscan(inhrel, SnapshotNow, 1, &skey);
-
-		while ((inhtup = heap_getnext(inhscan, ForwardScanDirection)) != NULL)
-		{
-			Form_pg_inherits inh = (Form_pg_inherits) GETSTRUCT(inhtup);
-			Oid			inhparent = inh->inhparent;
-
-			/* If this is the target superclass, we're done */
-			if (get_rel_type_id(inhparent) == superclassTypeId)
-			{
-				result = true;
-				break;
-			}
-
-			/* Else add to queue */
-			queue = lappend_oid(queue, inhparent);
-		}
-
-		heap_endscan(inhscan);
-
-		if (result)
-			break;
-	}
-
-	heap_close(inhrel, AccessShareLock);
-
-	list_free(visited);
-	list_free(queue);
-
-	return result;
-}
-
-
 /*
  * make_fn_arguments()
  *

src/include/catalog/pg_inherits.h

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/pg_inherits.h,v 1.26 2009/01/01 17:23:57 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_inherits.h,v 1.27 2009/05/12 00:56:05 tgl Exp $
  *
  * NOTES
  *	  the genbki.sh script reads this file and generates .bki
@@ -20,6 +20,7 @@
 #define PG_INHERITS_H
 
 #include "catalog/genbki.h"
+#include "nodes/pg_list.h"
 
 /* ----------------
  *		pg_inherits definition.  cpp turns this into
@@ -51,4 +52,17 @@ typedef FormData_pg_inherits *Form_pg_inherits;
 #define Anum_pg_inherits_inhparent		2
 #define Anum_pg_inherits_inhseqno		3
 
+/* ----------------
+ *		pg_inherits has no initial contents
+ * ----------------
+ */
+
+/*
+ * prototypes for functions in pg_inherits.c
+ */
+extern List *find_inheritance_children(Oid parentrelId);
+extern List *find_all_inheritors(Oid parentrelId);
+extern bool has_subclass(Oid relationId);
+extern bool typeInheritsFrom(Oid subclassTypeId, Oid superclassTypeId);
+
 #endif   /* PG_INHERITS_H */

src/include/optimizer/plancat.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/optimizer/plancat.h,v 1.52 2009/01/01 17:24:00 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/optimizer/plancat.h,v 1.53 2009/05/12 00:56:05 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -36,10 +36,6 @@ extern bool relation_excluded_by_constraints(PlannerInfo *root,
 
 extern List *build_physical_tlist(PlannerInfo *root, RelOptInfo *rel);
 
-extern List *find_inheritance_children(Oid inhparent);
-
-extern bool has_subclass(Oid relationId);
-
 extern bool has_unique_index(RelOptInfo *rel, AttrNumber attno);
 
 extern Selectivity restriction_selectivity(PlannerInfo *root,

src/include/optimizer/prep.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/optimizer/prep.h,v 1.65 2009/04/28 21:31:16 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/optimizer/prep.h,v 1.66 2009/05/12 00:56:05 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -46,8 +46,6 @@ extern List *preprocess_targetlist(PlannerInfo *root, List *tlist);
 extern Plan *plan_set_operations(PlannerInfo *root, double tuple_fraction,
 					List **sortClauses);
 
-extern List *find_all_inheritors(Oid parentrel);
-
 extern void expand_inherited_tables(PlannerInfo *root);
 
 extern Node *adjust_appendrel_attrs(Node *node, AppendRelInfo *appinfo);

src/include/parser/parse_func.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/parser/parse_func.h,v 1.64 2009/01/01 17:24:00 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/parser/parse_func.h,v 1.65 2009/05/12 00:56:05 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -63,8 +63,6 @@ extern FuncCandidateList func_select_candidate(int nargs,
 					  Oid *input_typeids,
 					  FuncCandidateList candidates);
 
-extern bool typeInheritsFrom(Oid subclassTypeId, Oid superclassTypeId);
-
 extern void make_fn_arguments(ParseState *pstate,
 				  List *fargs,
 				  Oid *actual_arg_types,